NOIP前刷水行动

2016.11.15

BZOJ1009:DP+矩阵乘法+KMP

BZOJ1898:矩阵乘法

BZOJ4101:贪心，考虑我们往右边撞的时候，我们会向左边冲

　　　　　　，于是枚举答案点利用一个指针计算即可！

2016.11.14

OI队内测试

2016.11.13

BZOJ4512：乱搞

BZOJ4102：DP+bfs

BZOJ4395：bfs

BZOJ3889：双键值最短路

BZOJ4512

#include <bits/stdc++.h>
using namespace std;
#define LL long long
int N,sx,sy,ans;
char s[];
bool vis[][],north[][],east[][];
int main(){
//    freopen("data.in","r",stdin);
//    freopen("A.out","w",stdout);
    scanf("%d%s",&N,s);
    sx=sy=;
    for (int i=;i<N;i++){
        vis[sx][sy]=;
        char ch=s[i];
        if (ch=='N'){
            sy++;
            if (!north[sx][sy-]&&vis[sx][sy])ans++;
            north[sx][sy-]=;
        }
        if (ch=='S'){
            sy--;
            if (!north[sx][sy]&&vis[sx][sy])ans++;
            north[sx][sy]=;
        }
        if (ch=='E'){
            sx++;
            if (!east[sx-][sy]&&vis[sx][sy])ans++;
            east[sx-][sy]=;
        }
        if (ch=='W'){
            sx--;
            if (!east[sx][sy]&&vis[sx][sy])ans++;
            east[sx][sy]=;
        }
    }
    printf("%d\n",ans);
}

BZOJ4102

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define ll long long
#define ld long double
#define N 1005
#define M N*(N+1)
using namespace std;
int n,p,tot;
int pre[M],v[M],now[N],f[N],dis[N][N];
bool vis[N];
queue<int>q;
struct data{
    int val,pos;
}a[N];
int read()
{
    int x=,f=; char ch;
    while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
    while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
    return x*f;
}
void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
}
bool  cmp(data a,data b){return a.val<b.val;
}
void bfs(int u)
{
    memset(vis,,sizeof(vis));
    q.push(u); dis[u][u]=; vis[u]=;
    while (!q.empty())
    {
        int x=q.front(); q.pop();
        for (int p=now[x]; p; p=pre[p])
        {
            int son=v[p];
            if (!vis[son])
            {
                dis[u][son]=dis[u][x]+;
                q.push(son); vis[son]=;
            }
        }
    }
}
int main()
{
    n=read(); p=read();
    for (int i=; i<=n; i++)
    {
        int x=read(),d=read();
        a[i].val=x; a[i].pos=i;
        for (int j=; j<=d; j++) {int y=read(); ins(i,y); ins(y,i);}
    }
    for (int i=; i<=n; i++) bfs(i);
    sort(a+,a+n+,cmp);
    for (int i=; i<=n; i++) f[i]=a[i].val;
    for (int i=; i<=n; i++)
        for (int j=; j<=i-; j++)
        {
            if (a[i].val>a[j].val && dis[a[i].pos][a[j].pos])
            {
                f[i]=max(f[i],f[j]-dis[a[i].pos][a[j].pos]*p+a[i].val);
            }
        }
    int ans=;
    for (int i=; i<=n; i++) ans=max(ans,f[i]);
    printf("%d\n",ans);
    return ;
}

BZOJ4395

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define ll long long
#define ld long double
#define N 205
#define M 40005
using namespace std;
int dx[]={,,,-},dy[]={,-,,};
int pre[M],v[M],now[N*N],tot;
int n,m,ans;
queue<int>q;
bool vis[N][N],lig[N][N];
int read()
{
    int x=,f=; char ch;
    while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
    while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
    return x*f;
}
int encode(int a,int b){return (a-)*n+b;
}
void ins(int a,int b){
    ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
}
int main()
{
    n=read(); m=read();
    for (int i=; i<=m; i++)
    {
        int a=read(),b=read(),c=read(),d=read();
        ins(encode(a,b),encode(c,d));
    }
    int last=; ans=;
    for (;;)
    {
        q.push(encode(,));
        memset(vis,,sizeof(vis)); vis[][]=; lig[][]=;
        while (!q.empty())
        {
            int pp=q.front(),x,y; q.pop(); //last++;
            for (int p=now[pp]; p; p=pre[p])
            {
                int son=v[p]; x=(son-)/n+,y=(son-)%n+;
                if (!lig[x][y]) lig[x][y]=,ans++;
            }
            x=(pp-)/n+,y=(pp-)%n+;
            for (int i=; i<; i++)
            {
                int xx=x+dx[i],yy=y+dy[i];
                if (xx< || xx>n || yy< || yy>n || !lig[xx][yy] || vis[xx][yy]) continue;
                vis[xx][yy]=; q.push(encode(xx,yy));
            }
        }
        if (last==ans) break;
        last=ans;
    }
    printf("%d\n",ans);
    return ;
}

BZOJ3889

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define ll long long
#define ld long double
#define inf 100000000000000
#define N 1005
using namespace std;
int s,t,m,n;
ll a[N][N],b[N][N],dis[N],d[N];
int c[N];
bool vis[N];
queue<int>q;
int read()
{
    int x=,f=; char ch;
    while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
    while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
    return x*f;
}
void spfa()
{
    for (int i=; i<=m; i++) dis[i]=inf;
    dis[s]=d[s]=; vis[s]=; q.push(s);
    while (!q.empty())
    {
        int x=q.front(); q.pop(); vis[x]=;
        //cout<<"         "<<x<<endl;
        for (int i=; i<=m; i++)
        {
        //    cout<<i<<" "<<dis[i]<<" "<<dis[x]<<" "<<a[x][i]<<endl;
            if (dis[i]>dis[x]+a[x][i] || ((dis[i]==dis[x]+a[x][i]) && d[i]>d[x]+b[x][i]))
            {
            //    cout<<"                "<<x<<" "<<i<<" "<<a[x][i]+dis[x]<<endl;
                dis[i]=dis[x]+a[x][i]; d[i]=d[x]+b[x][i];
                if (!vis[i]) vis[i]=,q.push(i);
            }
        }
        //|| (dis[i]==dis[x]+a[x][i] && d[i]>d[x]+b[x][i])
    }
}
int main()
{
    s=read(); t=read(); n=read();
    for (int i=; i<=; i++)
        for (int j=; j<=; j++) a[i][j]=inf;
    for (int i=; i<=n; i++)
    {
        int len=read(),cnt=read();
        for (int j=; j<=cnt; j++) c[j]=read(),m=max(m,c[j]);
        for (int j=; j<=cnt; j++)
            for (int k=j+; k<=cnt; k++)
            if (a[c[j]][c[k]]>len || ((a[c[j]][c[k]]==len) && (b[c[j]][c[k]]>(k-j)))) a[c[j]][c[k]]=len,b[c[j]][c[k]]=k-j;
    }
    spfa();
    if (dis[t]==inf) dis[t]=-,d[t]=-;
    cout<<dis[t]<<" "<<d[t]<<endl;
    return ;
}

2016.11.12

BZOJ3887: spfa（正边一次+反边一次）

BZOJ3886：状态压缩dp+二分（f[i]表示看电影状态为i的最长连续时间）

BZOJ4098：DP优化（f[i][j][k][l]：（i+j）==（k+l） 优化为f[i][j][k]：（i+j)满足滚动数组

BZOJ3888：把时间求出来+线段树

BZOJ3887

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
#define N 100005
#define M 200005
using namespace std;
int read()
{
    int x=,f=; char ch;
    while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
    while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
    return x*f;
}
int n,m;
int a[N],b[N];
int tot,pre[M],v[M],now[N];
int bel[N],low[N],dfn[N],num[N],total,ind,top,z[N];
int dist1[N],dist2[N];
bool inq[N],vis[N];
queue<int> q;
void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;}
void tarjan(int x)
{
    low[x]=dfn[x]=++ind;
    ++top; z[top]=x; inq[x]=;
    for (int p=now[x]; p; p=pre[p])
    {
        int son=v[p];
        if (!dfn[son]) tarjan(son),low[x]=min(low[x],low[son]);
        else if (inq[son]) low[x]=min(low[x],dfn[son]);
    }
    if (low[x]==dfn[x])
    {
        ++total; num[total]=; inq[x]=; bel[x]=total;
        while (z[top]!=x)
        {
            int son=z[top]; bel[son]=total; inq[son]=; num[total]++; top--;
        }
        top--;
    }
}
void build(int X)
{
    memset(now,,sizeof(now)); tot=;
    for (int i=; i<=m; i++)
    {
        int x=a[i],y=b[i];
        if (bel[x]!=bel[y])
        {
            if (X==) ins(bel[x],bel[y]); else ins(bel[y],bel[x]);
        }
    }
}
void spfa1()
{
    vis[bel[]]=; dist1[bel[]]=num[bel[]]; q.push(bel[]);
    while (!q.empty())
    {
        int x=q.front(); q.pop(); vis[x]=;
        for (int p=now[x]; p; p=pre[p])
        {
            int son=v[p];
            if (dist1[son]<dist1[x]+num[son])
            {
                dist1[son]=dist1[x]+num[son];
                if (!vis[son]) q.push(son),vis[son]=;
            }
        }
    }
}
void spfa2()
{
    vis[bel[]]=; dist2[bel[]]=num[bel[]]; q.push(bel[]);
    while (!q.empty())
    {
        int x=q.front(); q.pop(); vis[x]=;
        for (int p=now[x]; p; p=pre[p])
        {
            int son=v[p];
            if (dist2[son]<dist2[x]+num[son])
            {
                dist2[son]=dist2[x]+num[son];
                if (!vis[son]) q.push(son),vis[son]=;
            }
        }
    }
}
int main()
{
    n=read(); m=read();
    for (int i=; i<=m; i++) a[i]=read(),b[i]=read(),ins(a[i],b[i]);
    for (int i=; i<=n; i++) if (!dfn[i]) tarjan(i);
    build(); spfa1();
    build(); spfa2();
    int ans=;
    for (int i=; i<=m; i++) if (bel[a[i]]!=bel[b[i]] && dist1[bel[b[i]]] && dist2[bel[a[i]]])
    {
        ans=max(ans,dist1[bel[b[i]]]+dist2[bel[a[i]]]-num[bel[]]);
    }
    printf("%d\n",ans);
    return ;
}

BZOJ3886

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
int n,L;
int num[],len[],c[][];
int f[];
int read()
{
    int x=,f=; char ch;
    while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
    while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
    return x*f;
}
int find(int x,int s)
{
    int l=,r=num[x],Ans=-;
    while (l<=r)
    {
        int mid=(l+r)>>;
        if (c[x][mid]<=s) Ans=mid,l=mid+; else r=mid-;
    }
    return Ans;
}
int main()
{
    n=read(); L=read();
    for (int i=; i<=n; i++)
    {
        len[i]=read(); num[i]=read();
        for (int j=; j<=num[i]; j++) c[i][j]=read();
    }
    f[]=;
    int s=<<n,ans=0x7fffffff;
    for (int i=; i<s; i++) f[i]=-;
    for (int i=; i<s; i++)
    {
        if (f[i]==-) continue;
        int k=;
        if (f[i]>L)
        {
            for (int j=i; j; j>>=) if (j&) k++;
            ans=min(ans,k); continue;
        }
        for (int j=; j<=n; j++)
        {
            if (i&(<<(j-))) continue;
            int k=find(j,f[i]); if (k==-) continue;
            f[i|(<<(j-))]=max(f[i|(<<(j-))],c[j][k]+len[j]);
        }
    }
    if (ans==0x7fffffff) ans=-;
    printf("%d\n",ans);
    return ;
}

BZOJ4098

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#define N 505
#define mod 1000000007
#define add(a,b) (a=(a+b)%mod)
using namespace std;
int n,f[][N][N];
char s[N][N];
int main()
{
    scanf("%d",&n);
    for (int i=; i<=n; i++) scanf("%s",s[i]+);
    if(s[][]!=s[n][n])
    {
        puts("");
        return ;
    }
    int now=,last=;
    f[now][][]=;
    for (int h=; h<n; h++)
    {
        now^=; last^=;
        memset(f[now],,sizeof(f[now]));
        for (int i=; i<=h; i++)
        {
            int j=(h-i),a=i+,b=j+;
            for (int k=; k<=h; k++)
            {
                int l=h-k,x=n-l,y=n-k;
            /*    if (s[a+1][b]==s[x][y-1]) (f[now][i+1][k+1]+=f[last][i][k])%mod;
                if (s[a+1][b]==s[x-1][y]) (f[now][i+1][k]+=f[last][i][k])%mod;
                if (s[a][b+1]==s[x][y-1]) (f[now][i][k+1]+=f[last][i][k])%mod;
                if (s[a][b+1]==s[x-1][y]) (f[now][i][k]+=f[last][i][k])%mod;    */
                if(s[a+][b]==s[x-][y])add(f[now][i+][ k ],f[last][i][k]);
                if(s[a+][b]==s[x][y-])add(f[now][i+][k+],f[last][i][k]);
                if(s[a][b+]==s[x-][y])add(f[now][ i ][ k ],f[last][i][k]);
                if(s[a][b+]==s[x][y-])add(f[now][ i ][k+],f[last][i][k]);
            }
        }
    }
    int ans=;
    for (int i=; i<n; i++) add(ans,f[last][i][i]);
    printf("%d\n",ans);
    return ;
}

BZOJ3888

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#define N 50005
using namespace std;
int n,tot;
struct data{
    int h,l,r;
}a[N];
int b[*N],cov[N*];
int read()
{
    int x=,f=; char ch;
    while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
    while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
    return x*f;
}
bool cmp2(data a,data b){return a.h<b.h;
}
int get(int x,int c)
{
    return x>=?:-x*c;
}
int cover(int k,int l,int r,int x,int y)
{
    if (cov[k]) return ;
    if (x<=l && r<=y)
    {
        cov[k]=; return ;
    }
    bool ret=;
    int mid=(l+r)>>;
    if (x<=mid) ret|=cover(k*,l,mid,x,y);
    if (mid<y) ret|=cover(k*+,mid+,r,x,y);
    cov[k]=cov[k*]&cov[k*+];
    return ret;
}
int find(int x)
{
    int l=,r=tot,ans=;
    while (l<=r)
    {
        int mid=(l+r)>>;
        if (b[mid]<=x) ans=mid,l=mid+; else r=mid-;
    }
    return ans;
}
int main()
{
    n=read();
    for (int i=; i<=n; i++)
    {
        int x=read(),y=read(),c=read();
        int l=get(x+,c),r=get(x,c);
        a[i].l=l,a[i].r=r,a[i].h=y;
        b[++tot]=l; b[++tot]=r;
    }
    sort(b+,b+tot+);
    for (int i=; i<=n; i++) a[i].l=find(a[i].l),a[i].r=find(a[i].r)-;
    sort(a+,a+n+,cmp2);
    int ans=;
    for (int i=; i<=n; i++) ans+=cover(,,tot,a[i].l,a[i].r);
    printf("%d\n",ans);
    return ;
}

2016.11.11

BZOJ4396 ：贪心

BZOJ4397 ：前缀和

BZOJ3943 ：最小生成树

BZOJ4576：DP：这道题还可以网上有很多种写法

BZOJ4582：DP：之前看错题想了好久最后发现题目意思 好水

BZOJ4412：贪心：这道题也不错，我们首先将每个数减1，如果存在j-->x的子段和大于0，

　　　　　　　　　则说明一定有牛走出去，而我们可以知道在顺时针方向一定存在一个

　　　　　　　　　点没有牛越过去，于是我们找到那个点将环转化为链即可，而这个点

　　　　　　　　　一定是最大子段和的左节点，于是问题解决

2016.11.10

BZOJ1592 Usaco2008 Feb]Making the Grade 路面修整：离散+DP

BZOJ1051 HAOI 受欢迎的牛 ：tarjan

BZOJ2442 修建草坪 ：单调队列优化DP

BZOJ3890 Meeting time : 分层DP

BZOJ4390 Max Flow ：树上差分

BZOJ4525 ：二分答案判定

BZOJ4511 ：DP

 BZOJ1592

 #include<iostream>
 #include<algorithm>
 #include<cstring>
 #include<cstdio>
 #include<cmath>
 #define N 3005
 #define inf 0x7fffffff
 using namespace std;
 int n,m,ans,a[N],c[N],f[N][N];
 int read()
 {
   int x=,f=; char ch;
   while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
   while (x=x*+ch-'',ch=getchar(),ch>='' && ch<='');
   return x*f;
 }
 void solve()
 {
   sort(c+,c+n+);
   m=unique(c+,c+n+)-(c+);
   for (int i=; i<=n; i++) f[i][]=inf/;
   for (int i=; i<=n; i++)
     {
       for (int j=; j<=m; j++)
     {
       f[i][j]=min(f[i-][j]+abs(a[i]-c[j]),f[i][j-]);
     }
     }
   ans=f[n][m];
   for (int i=; i<=n; i++) f[i][m+]=inf/;
   for (int i=; i<=n; i++)
     {
       for (int j=m; j>=; j--)
     {
       f[i][j]=min(f[i-][j]+abs(a[i]-c[j]),f[i][j+]);
     }
     }
   ans=min(ans,f[n][]);
 }
 int main()
 {
   n=read();
   for (int i=; i<=n; i++)  c[i]=a[i]=read();
   solve();
   printf("%d\n",ans);
   return ;
 }

 BZOJ1051

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 10005
 #define M 50005
 using namespace std;
 int n,m,ans,u[M],V[M];
 int now[N],pre[M],v[M],tot;
 int ind,top,total,z[N],dfn[N],low[N],num[N],in[N],out[N],belong[N];
 bool vis[N],inq[N];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 void ins(int a,int b){
     ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
 }
 void dfs(int x)
 {

     dfn[x]=low[x]=++ind;
     vis[x]=inq[x]=; z[++top]=x;
     for (int p=now[x]; p; p=pre[p])
     {
         int son=v[p];
         if (!dfn[son]) {dfs(son); low[x]=min(low[x],low[son]);}
         else if (inq[son]) low[x]=min(low[x],dfn[son]);
     }
     if (low[x]==dfn[x])
     {
         ++total;
         belong[x]=total; inq[x]=; num[total]=;
         while (z[top]!=x)
         {
             int son=z[top];
             belong[son]=total; inq[son]=; num[total]++;
             top--;
         }
         top--;
     }
 }
 int main()
 {
     n=read(); m=read();
     for (int i=; i<=m; i++)
     {
         int x=read(),y=read();
         u[i]=x; V[i]=y;
         ins(x,y);
     }
     for (int i=; i<=n; i++) if (!dfn[i]) dfs(i);
     for (int i=; i<=m; i++) if (belong[u[i]]!=belong[V[i]])
     {
     //    cout<<" "<<belong[u[i]]<<" "<<belong[V[i]]<<endl;
         ++out[belong[u[i]]]; ++in[belong[V[i]]];
     }
 //    for (int i=1; i<=total; i++) cout<<num[i]<<endl;
     int sum=;
     for (int i=; i<=total; i++)
     {
         if (!out[i]) {ans=num[i]; sum++; if (sum>=) break;}
     }
 //    cout<<ans<<endl;
     if (sum>) ans=; printf("%d\n",ans);
     return ;
 }

 BZOJ 

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 100005
 using namespace std;
 int n,k,head,tail;
 ll ans,sum,f[N];
 int a[N],pos[N];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int main()
 {
     n=read(); k=read();
     for (int i=; i<=n; i++) a[i]=read(),sum+=a[i];
     for (int i=; i<=n; i++)
     {
         while (head<=tail && pos[head]<i-k-) head++;
         f[i]=f[pos[head]]+a[i];
         while (head<=tail && f[pos[tail]]>=f[i]) tail--;
         ++tail; pos[tail]=i;
     }
     ans=;
     for (int i=n-k; i<=n; i++) ans=min(ans,f[i]);
     printf("%lld\n",sum-ans);
     return ;
 }

 BZOJ3890

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define N 105
 #define M (N*(N+1))
 #define ll long long
 using namespace std;
 int pre[M],v[M],val1[M],val2[M],now[N],n,m,tot;
 bool f[N][M],g[N][M];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 void ins(int a,int b,int c,int d)
 {
     ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; val1[tot]=c; val2[tot]=d;
 }
 int main()
 {
     n=read(); m=read();
     for (int i=; i<=m; i++)
     {
         int u=read(),v=read(),a=read(),b=read();
         ins(u,v,a,b);
     }
     f[][]=g[][]=;
     for (int i=; i<=n-; i++)
     {
         for (int p=now[i]; p; p=pre[p])
         {
             int son=v[p];
             for (int j=val1[p]; j<=; j++) f[son][j]|=f[i][j-val1[p]];
             for (int j=val2[p]; j<=; j++) g[son][j]|=g[i][j-val2[p]];
         }
     }
     bool bo=false;
     for (int i=; i<=; i++)
     if (g[n][i] && f[n][i])
     {
         bo=true;
         printf("%d\n",i);
         break;
     }
     if (!bo) printf("IMPOSSIBLE\n");
     return ;
  } 

 BZOJ4390

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define N 60005
 #define M N*2
 #define ll long long
 using namespace std;
 int pre[M],v[M],now[N],tot,n,k,ans;
 int f[N][],bin[],deep[N],val[N];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;
 }
 void dfs(int x)
 {
      for (int i=; i<= && bin[i]<=deep[x]; i++) f[x][i]=f[f[x][i-]][i-];
      for (int p=now[x]; p; p=pre[p])
      {
          int son=v[p]; if (son==f[x][]) continue;
          deep[son]=deep[x]+; f[son][]=x;
          dfs(son);
      }
 }
 int lca(int x,int y)
 {
     if (deep[x]<deep[y]) swap(x,y);
     int t=deep[x]-deep[y];
     for (int i=; bin[i]<=t; i++)
     {
         if (t&bin[i]) x=f[x][i];
     }
     for (int i=; i>=; i--) if (f[x][i]!=f[y][i]) x=f[x][i],y=f[y][i];
     if (x==y) return x;
     return f[x][];
 }
 void dfs2(int x,int fa)
 {
     for (int p=now[x]; p; p=pre[p])
     {
         int son=v[p]; if (son==fa) continue;
         dfs2(son,x); val[x]+=val[son];
     }
     ans=max(ans,val[x]);
 }
 int main()
 {
     n=read(); k=read();
     for (int i=; i<n; i++)
     {
         int x=read(),y=read();
         ins(x,y); ins(y,x);
     }
     bin[]=; for (int i=; i<=; i++) bin[i]=bin[i-]*;
     deep[]=; dfs();
     for (int i=; i<=k; i++)
     {
         int x=read(),y=read();
         int t=lca(x,y);
         val[x]++; val[y]++; val[t]--; val[f[t][]]--;
     }
     dfs2(,);
     printf("%d\n",ans);
     return ;
 }

 BZOJ4525

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define inf 0x7ffffff
 using namespace std;
 int n,k,ans;
 int a[];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 bool pd(int mid)
 {
     int l=;
     for (int i=; i<=k; i++)
     {
         int pos=a[l+];
         while (l+<=n && ((a[l+]-pos)<=*mid)) l++;
     }
     if (l>=n) return true;
     return false;
 }
 int main()
 {
     n=read(); k=read();
     for (int i=; i<=n; i++) a[i]=read();
     sort(a+,a+n+);
     int l=,r=inf-;
     while (l<=r)
     {
         int mid=(l+r)>>;
         if (pd(mid)) ans=mid,r=mid-; else l=mid+;
     }
     printf("%d\n",ans);
     return ;
 }

 BZOJ4511

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 50005
 using namespace std;
 int ans,n,a[N],f[N][];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int main()
 {
     n=read();
     for (int i=; i<=n; i++) a[i]=read()%;
     memset(f,-,sizeof(f));
     f[][]=; for (int i=; i<=n; i++) f[i][a[i]]=;
     for (int i=; i<=n; i++)
         for (int j=; j<=; j++)
         if (f[i-][j]!=-) f[i][(j+a[i])%]=max(f[i][(j+a[i])%],f[i-][j]+);
     for (int i=; i<=n; i++) ans=max(ans,f[i][]);
     printf("%d\n",ans);
     return ;
 }

代码集合

2016.11.9

BZOJ1711： 最大流

BZOJ1642: 排序+DP

 BZOJ1711

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #include<queue>
 #define inf 0x7fffffff
 #define ll long long
 #define N 505
 #define M 50005
 using namespace std;
 int n,F,D,head,tail,list[N<<],tot=,S,T,ans=;
 int pre[M],v[M],cap[M],now[N],deep[N];
 queue<int>q;
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 void ins(int a,int b,int c){
     ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; cap[tot]=c;
     ++tot; pre[tot]=now[b]; now[b]=tot; v[tot]=a; cap[tot]=;
 }
 void init_build()
 {
     n=read(); F=read(); D=read();
     S=; T=n*+F+D+;
     for (int i=; i<=F; i++) ins(S,i,);
     for (int i=F+n*+; i<=F+n*+D; i++) ins(i,T,);
     for (int i=; i<=n; i++)
     {
         int A=read(),B=read();
         for (int j=; j<=A; j++) {int x=read(); ins(x,F+i,);}
         for (int j=; j<=B; j++) {int x=read(); ins(F+n+i,F+n*+x,);}
     }
     for (int i=;i<=n;i++) ins(F+i,F+i+n,);
 }
 bool bfs()
 {
     for (int i=S;i<=T;i++) deep[i]=-;
     deep[S]=; head=,tail=,list[]=S;
     while (head<tail)
     {
         int x=list[++head];
         for (int p=now[x]; p; p=pre[p])
         {
             int son=v[p];
             if (cap[p] && deep[son]==-)
             {
                 deep[son]=deep[x]+;
                 if (son==T) return ;
                 list[++tail]=son;
             }
         }
     }
     return ;
 }
 int find(int x,int tmpflow)
 {
     int temp,re;
     if (x==T) return tmpflow;
     re=temp=;
     for (int p=now[x]; p; p=pre[p])
     {
         int son=v[p];
         if (cap[p] && deep[son]==deep[x]+)
         {
             temp=find(son,min(tmpflow,cap[p]));
             cap[p]-=temp;
             cap[p^]+=temp;
             re+=temp;
             tmpflow-=temp;
             if (tmpflow==) break;
         }
     }
     deep[x]=-;
     return re;
 }
 void dinic()
 {
     ans=;
     while (bfs())
     {
         ans+=find(S,inf);
     }
 }
 int main()
 {
     tot=;
     init_build();
     dinic();
     printf("%d\n",ans);
     return ;
 }

 BZOJ 

 #include<iostream>
 #include<cstring>
 #include<cmath>
 #include<cstdio>
 #include<algorithm>
 using namespace std;
 int n,m,r,ans=;
 int read(){
   int x=,f=; char ch;
   while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
   while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
   return x*f;
 }
 struct data{
   int l,r,val;
 }a[];
 int f[];
 bool cmp(data a,data b)
 {
   return a.l==b.l?a.r<b.r:a.l<b.l;
 }
 int main()
 {
   n=read(); m=read()+; r=read();
   a[].l=a[].r=-; a[].val=;
   for (int i=; i<=m; i++)
     {
       a[i].l=read(),a[i].r=read()-,a[i].val=read();
     }
   sort(a+,a+m+,cmp);
   for (int i=; i<=m; i++)
     {
       for (int j=; j<=i-; j++)
     {
       if (a[j].r+r<a[i].l)
         {
           f[i]=max(f[i],f[j]+a[i].val);
           ans=max(ans,f[i]);
         }
     }
     }
   printf("%d\n",ans);
   return ;
 }

代码集合

2016.11.8

BZOJ1708：背包

BZOJ1690：01分数规划+spfa+二分

BZOJ1669：LIS问题+单调栈

 BZOJ 

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 using namespace std;
 int n,m;
 ll f[];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int main()
 {
     n=read(); m=read(); f[]=;
     for (int i=; i<=n; i++)
     {
         int x=read();
         for (int i=x; i<=m; i++) f[i]+=f[i-x];
     }
     printf("%lld\n",f[m]);
     return ;
 }

 BZOJ1690
 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 1005
 #define M 5005
 using namespace std;
 int n,m,tot;
 int a[N],now[N],pre[M],v[M];
 double ans,mid,val[M],value[N],dis[N];
 bool vis[N];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 void ins(int a,int b,int c){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; val[tot]=c;
 }
 bool spfa(int x)
 {
     vis[x]=;
     for (int p=now[x]; p; p=pre[p])
     {
         int son=v[p];
         if (dis[son]<dis[x]+value[son]-mid*val[p])
         {
             if (!vis[son])
             {
                 dis[son]=dis[x]+value[son]-mid*val[p];
                 if (spfa(son)) return ;
              }
             else return ;
         }
     }
     return vis[x]=;
 }
 int main()
 {
     n=read(); m=read();
     for (int i=; i<=n; i++) value[i]=read();
     for (int i=; i<=m; i++)
     {
         int a=read(),b=read(),c=read(); ins(a,b,c);
     }
     double l=,r=,eps=1e-;
     while (r-l>eps)
     {
         memset(dis,,sizeof(dis));
         memset(vis,,sizeof(vis));
         mid=(l+r)/2.0; dis[]=0.0;
         if (spfa()) ans=mid,l=mid; else r=mid;
      }
      printf("%0.2lf\n",ans);
     return ;
 }

 BZOJ1669

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define N 5005
 #define ll long long
 using namespace std;
 int n,tot;
 int b[N];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int main()
 {
     int n=read(),tot=;
     for (int i=; i<=n; i++)
     {
         int x=read();
         if (x>b[tot])
         {
             tot++; b[tot]=x;
         }
         else
         {
             int l=tot;
             while (l>= && b[l]>=x) l--;
             //cout<<" "<<l<<endl;
             b[l+]=x;
         }
     }
     printf("%d\n",tot);
     return ;
 }

代码集合

2016.11.7

BZOJ3298：打表找规律

BZOJ3296：并查集

BZOJ1599：模拟

BZOJ1232：最小生成树

 BZOJ3298

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 1000005
 using namespace std;
 int n,m,f[N];
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int main()
 {
     n=read()+; m=read()+;
     f[]=; int t=;
     for (int i=; i<=m; i++)
     {
         if (f[i]) continue;
         t++; f[i]=i+t; if (i+t<=m) f[i+t]=i;
      }
      int T=read();
      while (T--)
      {
          int x=read()+,y=read()+;
          if (f[x]==y) printf("Farmer John\n"); else printf("Bessie\n");
      }
     return ;
  } 

 BZOJ3296

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 40005
 using namespace std;
 int fa[N],id[N],n,m,ans;
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]);
 }
 int main()
 {
     n=read(); m=read();
     for (int i=; i<=n; i++) fa[i]=i;
     for (int i=; i<=n; i++)
     {
         int k=read();
         for (int j=; j<=k; j++){int x=read(); if (!id[x]) id[x]=i; else {fa[find(id[x])]=find(i); id[x]=i;}}
     }
     for (int i=; i<=n; i++) if (find(i)==i) ans++;
     printf("%d\n",ans-);
     return ;
 }

 BZOJ1599

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 using namespace std;
 int sum[],ans;
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 int main()
 {
     int a=read(),b=read(),c=read();
     for (int i=; i<=a; i++)
         for (int j=; j<=b; j++)
             for (int k=; k<=c; k++) sum[i+j+k]++;
     sum[]=; ans=; for (int i=; i<=a+b+c; i++) if (sum[i]>sum[ans]) ans=i;
     printf("%d\n",ans);
     return ;
 }

 BZOJ1232

 #include<iostream>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 #include<cstdio>
 #define ll long long
 #define N 100005
 using namespace std;
 int n,m;
 struct data{
     int u,v,val;
 }a[N];
 int c[N],Min=0x7fffffff,ans=,fa[N],cnt=;
 int read()
 {
     int x=,f=; char ch;
     while (ch=getchar(),ch<''||ch>'') if (ch=='-') f=-;
     while (x=x*+ch-'',ch=getchar(),ch>=''&&ch<='');
     return x*f;
 }
 bool cmp(data a,data b){return a.val<b.val;
 }
 int find(int x) {return x==fa[x]?x:fa[x]=find(fa[x]);}
 int main()
 {
     n=read(); m=read();
     for (int i=; i<=n; i++) fa[i]=i;
     for (int i=; i<=n; i++) c[i]=read();
     for (int i=; i<=m; i++) a[i].u=read(),a[i].v=read(),a[i].val=read()*+c[a[i].u]+c[a[i].v];
     sort(a+,a+m+,cmp);
     for (int i=; i<=m; i++)
     {
         int u=a[i].u,v=a[i].v,val=a[i].val;
         int fu=find(u),fv=find(v);
         if (fv!=fu)
         {
             fa[fv]=fu; Min=min(Min,min(c[u],c[v]));
             ans+=val; cnt++; if (cnt==n-) break;
         }
     }
     printf("%d\n",ans+Min);
     return ;
 }

代码集合