spfa毒瘤算法

终于知道怎么卡spfa(不优化)这一毒瘤算法了

下面就是造数据代码,点数才1e5,边数379980

随便测了一组数据:

count: 831841219(入队次数)

68917.096 ms(足够t到死了)

//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast,no-stack-protector")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pi acos(-1.0)
#define ll long long
#define vi vector<int>
#define mod 1000000007
#define ld long double
#define C 0.5772156649
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#define pll pair<ll,ll>
#define pil pair<int,ll>
#define pli pair<ll,int>
#define pii pair<int,int>
#define cd complex<double>
#define ull unsigned long long
#define base 1000000000000000000
#define Max(a,b) ((a)>(b)?(a):(b))
#define Min(a,b) ((a)<(b)?(a):(b))
#define fio ios::sync_with_stdio(false);cin.tie(0)
template<typename T>
inline T const& MAX(T const &a,T const &b){return a>b?a:b;}
template<typename T>
inline T const& MIN(T const &a,T const &b){return a<b?a:b;}
inline void add(ll &a,ll b){a+=b;if(a>=mod)a-=mod;}
inline void sub(ll &a,ll b){a-=b;if(a<0)a+=mod;}
inline ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
inline ll qp(ll a,ll b){ll ans=1;while(b){if(b&1)ans=ans*a%mod;a=a*a%mod,b>>=1;}return ans;}
inline ll qp(ll a,ll b,ll c){ll ans=1;while(b){if(b&1)ans=ans*a%c;a=a*a%c,b>>=1;}return ans;}

using namespace std;

const double eps=1e-8;
const ll INF=0x3f3f3f3f3f3f3f3f;
const int N=100000+10,maxn=400000+10,inf=0x3f3f3f3f;

struct edge{int a,b,c;};
vector<edge>v;
int main()
{
    srand(time(0));
    freopen("a.txt","w",stdout);
    int n=10,m=10000;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            if(j!=m)
            {
                v.pb({(i-1)*m+j,(i-1)*m+j+1,rand()%100000+1});
                v.pb({(i-1)*m+j+1,(i-1)*m+j,rand()%100000+1});
            }
            if(i!=n)
            {
                v.pb({(i-1)*m+j,i*m+j,1});
                v.pb({i*m+j,(i-1)*m+j,1});
            }
        }
    }
    printf("%d %d\n",n*m,v.size());
    random_shuffle(v.begin(),v.end());
    for(int i=0;i<v.size();i++)
        printf("%d %d %d\n",v[i].a,v[i].b,v[i].c);
    return 0;
}
/********************

********************/

spfa代码

//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast,no-stack-protector")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pi acos(-1.0)
#define ll long long
#define vi vector<int>
#define mod 1000000007
#define ld long double
#define C 0.5772156649
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#define pll pair<ll,ll>
#define pil pair<int,ll>
#define pli pair<ll,int>
#define pii pair<int,int>
#define cd complex<double>
#define ull unsigned long long
#define base 1000000000000000000
#define Max(a,b) ((a)>(b)?(a):(b))
#define Min(a,b) ((a)<(b)?(a):(b))
#define fio ios::sync_with_stdio(false);cin.tie(0)
template<typename T>
inline T const& MAX(T const &a,T const &b){return a>b?a:b;}
template<typename T>
inline T const& MIN(T const &a,T const &b){return a<b?a:b;}
inline void add(ll &a,ll b){a+=b;if(a>=mod)a-=mod;}
inline void sub(ll &a,ll b){a-=b;if(a<0)a+=mod;}
inline ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
inline ll qp(ll a,ll b){ll ans=1;while(b){if(b&1)ans=ans*a%mod;a=a*a%mod,b>>=1;}return ans;}
inline ll qp(ll a,ll b,ll c){ll ans=1;while(b){if(b&1)ans=ans*a%c;a=a*a%c,b>>=1;}return ans;}

using namespace std;

const double eps=1e-8;
const ll INF=0x3f3f3f3f3f3f3f3f;
const int N=1000000+10,maxn=4000000+10,inf=0x3f3f3f3f;

struct edge{
    int to,Next,c;
}e[maxn];
int cnt,head[N];
void init()
{
    cnt=0;
    memset(head,-1,sizeof head);
}
void add(int u,int v,int c)
{
    e[cnt].to=v;
    e[cnt].c=c;
    e[cnt].Next=head[u];
    head[u]=cnt++;
}
bool vis[N];
ll dis[N];
void spfa()
{
    memset(vis,0,sizeof vis);
    memset(dis,INF,sizeof dis);
    vis[1]=1;dis[1]=0;
    queue<int>q;
    q.push(1);
    int co=0;
    while(!q.empty())
    {
        int u=q.front();q.pop();
        vis[u]=0;
        for(int i=head[u];~i;i=e[i].Next)
        {
            int x=e[i].to;
            if(dis[x]>dis[u]+e[i].c)
            {
                dis[x]=dis[u]+e[i].c;
                if(!vis[x])
                {
                    vis[x]=1;
                    q.push(x);
                    co++;
                }
            }
        }
    }
    printf("count: %d\n",co);
}
int main()
{
    int a=clock();
    freopen("a.txt","r",stdin);
    init();
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=0;i<m;i++)
    {
        int a,b,c;
        scanf("%d%d%d",&a,&b,&c);
        add(a,b,c);
    }
    spfa();
    printf("%d\n",dis[n]);
    int b=clock();
    printf("%.3f ms\n",1.0*(b-a)/1000);
    return 0;
}
/********************

********************/