Codeforces Round #520 (Div. 2)

Codeforces Round #520 (Div. 2)

https://codeforces.com/contest/1062

A

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 100005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long mod=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int a[];

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     int n;
     cin>>n;
     if(n==) {
         cout<<<<endl;
         return ;
     }
     for(int i=;i<=n;i++) cin>>a[i];
     a[]=,a[n+]=;
     int ans=,Max=;
     for(int i=;i<=n+;i++){
         if(a[i]-a[i-]==){
             Max++;
         }
         else{
             ans=max(ans,Max-);
             Max=;
         }

     }
     ans=max(ans,Max-);
     cout<<ans<<endl;
 }

B

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 100005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long mod=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int a[];

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     ll n;
     cin>>n;
     ll tmp=n;
     ll num=;
     for(int i=;i<=n;i++){
         if(tmp%i==){
             num*=i;
             while(tmp%i==){
                 tmp/=i;
             }
         }
     }
     ll ans=;
     tmp=num;
     while(num%n){
         num*=num;
         ans++;
     }
     cout<<tmp<<" "<<(ans+(num>n))<<endl;
 }

C

数论+推公式

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 100005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long mod=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 string str;
 ll sum[];

 ll pow_mul(ll a,ll b){
     ll ans=;
     while(b){
         if(b&)
             ans=ans*a%mod;
         b>>=;
         a=a*a%mod;
     }
     return ans;
 }

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     int n,q;
     cin>>n>>q;
     cin>>str;
     for(int i=;i<n;i++){
         sum[i+]=sum[i]+str[i]-'';
     }
     int l,r;
     while(q--){
         cin>>l>>r;
         ll ans=pow_mul(,sum[r]-sum[l-])-;
         if(ans==-) ans+=mod;
         ans=(ans+ans*(pow_mul(,r-l++sum[l-]-sum[r])-+mod)%mod)%mod;
         cout<<ans<<endl;
     }
 }

D

数论

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 100005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long mod=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     int n;
     cin>>n;
     ll ans=;
     for(int i=;i<=n;i++){
         for(int j=i+i;j<=n;j+=i){
             ans+=j/i;
         }
     }
     cout<<ans*<<endl;
 }

E

lca+线段树+倍增

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 100005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long mod=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 //int phi[maxn];

 vector<int>ve[maxn];

 int dep[maxn],parent[maxn][],n,cnt;
 int Max[maxn<<],Min[maxn<<],id[maxn],s[maxn];

 void dfs(int now,int fa,int deep){
     dep[now]=deep;
     parent[now][]=fa;
     s[now]=++cnt;
     id[cnt]=now;
     for(int i=;i<ve[now].size();i++){
         dfs(ve[now][i],now,deep+);
     }
 }

 void Init(){
     for(int j=;j<;j++){
         for(int i=;i<=n;i++){
             parent[i][j]=parent[parent[i][j-]][j-];
         }
     }
 }

 int lca(int x,int y){
     if(dep[x]<dep[y]) swap(x,y);
     for(int i=;i>=;i--){
         if(dep[parent[x][i]]>=dep[y]){
             x=parent[x][i];
         }
     }
     if(x==y) return dep[x]-;
     for(int i=;i>=;i--){
         if(parent[x][i]!=parent[y][i]){
             x=parent[x][i];
             y=parent[y][i];
         }
     }
     return dep[parent[x][]]-;
 }

 int query1(int L,int R,int l,int r,int rt){
     if(L<=l&&R>=r) return Max[rt];
     int mid=l+r>>;
     int ans=;
     if(L<=mid) ans=max(ans,query1(L,R,lson));
     if(R>mid) ans=max(ans,query1(L,R,rson));
     return ans;
 }

 int query2(int L,int R,int l,int r,int rt){
     if(L<=l&&R>=r) return Min[rt];
     int mid=l+r>>;
     int ans=0x3f3f3f3f;
     if(L<=mid) ans=min(ans,query2(L,R,lson));
     if(R>mid) ans=min(ans,query2(L,R,rson));
     return ans;
 }

 void push_up(int rt){
     Max[rt]=max(Max[rt<<],Max[rt<<|]);
     Min[rt]=min(Min[rt<<],Min[rt<<|]);
 }

 void update(int L,int v,int l,int r,int rt){
     if(l==r){
         Max[rt]=Min[rt]=v;
         return;
     }
     int mid=l+r>>;
     if(L<=mid) update(L,v,lson);
     else update(L,v,rson);
     push_up(rt);
 }

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     int q;
     cin>>n>>q;
     int x,y;
     for(int i=;i<=n;i++){
         cin>>x;
         ve[x].pb(i);
     }
     dfs(,,);
     Init();
     for(int i=;i<=n;i++){
         update(i,s[i],,n,);
     }
     while(q--){
         cin>>x>>y;
         int min1=query2(x,y,,n,);
         int max1=query1(x,y,,n,);
         update(id[min1],0x3f3f3f3f,,n,);
         int min2=query2(x,y,,n,);
         update(id[min1],min1,,n,);
         update(id[max1],,,n,);
         int max2=query1(x,y,,n,);
         update(id[max1],max1,,n,);///?
         int ans1=lca(id[min1],id[max2]),ans2=lca(id[min2],id[max1]);
         if(ans1>=ans2){
             cout<<id[max1]<<" "<<ans1<<endl;
         }
         else{
             cout<<id[min1]<<" "<<ans2<<endl;
         }
     }

 }

F

拓扑排序

参考博客：https://www.cnblogs.com/yqgAKIOI/p/10012279.html

 #include<bits/stdc++.h>
 using namespace std;
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define sqr(x) ((x)*(x))
 #define pb push_back
 #define eb emplace_back
 #define maxn 300005
 #define eps 1e-8
 #define pi acos(-1.0)
 #define rep(k,i,j) for(int k=i;k<j;k++)
 typedef long long ll;
 typedef pair<int,int> pii;
 typedef pair<long long,int>pli;
 typedef pair<int,char> pic;
 typedef pair<pair<int,string>,pii> ppp;
 typedef unsigned long long ull;
 const long long mod=1e9+;
 /*#ifndef ONLINE_JUDGE
         freopen("1.txt","r",stdin);
 #endif */

 int n,m;
 int a[maxn],b[maxn],d[maxn],cnt[maxn];
 vector<int>ve[maxn];

 void topsort(int a[],int b[]){
     for(int i=;i<n;i++) ve[i].clear();
     for(int i=;i<m;i++){
         ve[a[i]].pb(b[i]);
         d[b[i]]++;
     }
     int num=n;
     queue<int>Q;
     for(int i=;i<n;i++){
         if(!d[i]){
             Q.push(i);
             num--;
         }
     }
     while(!Q.empty()){
         int now=Q.front();
         Q.pop();
         if(Q.empty()) cnt[now]+=num;
         else if(Q.size()==){
             int tmp=;
             for(int i=,y=Q.front();i<ve[y].size();i++){
                 tmp&=(d[ve[y][i]]>);
             }
             cnt[now]+=num*tmp;
         }
         for(int i=;i<ve[now].size();i++)
             if(!--d[ve[now][i]]){
                 Q.push(ve[now][i]);
                 num--;
             }
     }

 }

 int main(){
     #ifndef ONLINE_JUDGE
      //   freopen("1.txt","r",stdin);
     #endif
     std::ios::sync_with_stdio(false);
     cin>>n>>m;
     for(int i=;i<m;i++){
         cin>>a[i]>>b[i];
         a[i]--,b[i]--;
     }
     topsort(a,b);
     topsort(b,a);
     int ans=;
     for(int i=;i<n;i++)
         ans+=(cnt[i]+>=n);
     cout<<ans<<endl;

 }