kunagbin-ISAP 邻接表形式模板

关键还是建图，超级源点和超级汇点是一种很好的思想

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
using namespace std;
#define MAXN 100010
#define MAXM 400010
#define INF 0x3f3f3f3f
struct Edge
{
  int to,next,cap,flow;
} edge[MAXM];
int tol;
int head[MAXN];
int gap[MAXN],dep[MAXN],pre[MAXN],cur[MAXN];

void init()
{
    tol=0;
    memset(head,-1,sizeof head);
}

void addedge(int u,int v,int w,int rw=0)
{
    edge[tol].to=v;
    edge[tol].cap=w;
    edge[tol].next=head[u];
    edge[tol].flow=0;
    head[u]=tol++;
    edge[tol].to=u;
    edge[tol].cap=rw;
    edge[tol].next=head[v];
    edge[tol].flow=0;
    head[v]=tol++;
}

int sap(int start,int end,int N)
{
    memset(gap,0,sizeof gap);
    memset(dep,0,sizeof dep);
    memcpy(cur,head,sizeof head);
    int u=start;
    pre[u]=-1;
    gap[0]=N;
    int ans=0;
    while(dep[start]<N)
    {
        if(u==end)
        {
            int Min=INF;
            for(int i=pre[u];i!=-1;i=pre[edge[i^1].to])
                if(Min>edge[i].cap-edge[i].flow)
                  Min=edge[i].cap-edge[i].flow;
            for(int i=pre[u];i!=-1;i=pre[edge[i^1].to])
            {
                edge[i].flow+=Min;
                edge[i^1].flow-=Min;
            }
            u=start;
            ans+=Min;
            continue;
        }
        bool flag=false;
        int v;
        for(int i=cur[u];i!=-1;i=edge[i].next)
        {
            v=edge[i].to;
            if(edge[i].cap-edge[i].flow&&dep[v]+1==dep[u])
            {
                flag=true;
                cur[u]=pre[v]=i;
                break;
            }
        }
        if(flag)
        {
            u=v;
            continue;
        }
        int Min=N;
        for(int i=head[u];i!=-1;i=edge[i].next)
          if(edge[i].cap-edge[i].flow&&dep[edge[i].to]<Min)
        {
            Min=dep[edge[i].to];
            cur[u]=i;
        }
        gap[dep[u]]--;
        if(!gap[dep[u]]) return ans;
        dep[u]=Min+1;
        gap[dep[u]]++;
        if(u!=start) u=edge[pre[u]^1].to;
    }
    return ans;
}

int main()
{
    int T;
    cin>>T;
    int g=0;
    while(T--)
    {
        g++;
        init();
        int n,m;
        cin>>n>>m;
        for(int i=1;i<=m;i++)
        {
            int u,v,w;
            cin>>u>>v>>w;
            addedge(u,v,w);
        }
        cout<<"Case "<<g<<": "<<sap(1,n,n)<<endl;
    }
    return 0;
}