最大流模板

Dinic模板：

HDU 4280

C++ 加了栈还是TLE ，然后手写对了快了三秒

//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <iostream>
#include <string>
#include <queue>
#include<string.h>

using namespace std;

#define N 100010
#define inf 0x3f3f3f3f

struct edge
{
  int next,v,c;
}e[N<<1];
int n,m;
int tot,head[N],d[N];
int q[N];

int min(int a,int b)
{
   return a<b?a:b;
}

void add(int u,int v,int c)
{
 e[tot].v=v;e[tot].c=c;
 e[tot].next=head[u];head[u]=tot++;

 e[tot].v=u;e[tot].c=c;
 e[tot].next=head[v];head[v]=tot++;
}

int  bfs(int s,int t)
{
   memset(d,-1,sizeof(d));
   int f=0,r=0;
   q[r++]=s;
   d[s]=0;
   
   while (f<r)
   {
         int u=q[f++];
         if (u==t) return 1;
         for (int i=head[u];i!=-1;i=e[i].next)
         {
           int v=e[i].v;
           if (d[v]==-1&&e[i].c>0)
           {
             d[v]=d[u]+1;
             q[r++]=v;
           }
         }
   }
   return 0;
}

int dfs(int s,int t,int b)
{
  int r=0;
  if (s==t) return b;
  for (int i=head[s];i!=-1&&r<b;i=e[i].next)
  {
     int v=e[i].v;
     if (e[i].c>0&&d[v]==d[s]+1)
     {
       int x=min(e[i].c,b-r);
       x=dfs(v,t,x);
       r+=x;
       e[i].c-=x;
       e[i^1].c+=x;
     }
  }
  if (!r) d[s]-=2;
  return r;
}

int dinic(int s,int t)
{
  int ans=0,tmp;
  while (bfs(s,t))
  {
     while (tmp=dfs(s,t,inf)) ans+=tmp;
  }
  return ans;
}

int main()
{
   int T;
   scanf("%d",&T);
   while (T--)
   {
       memset(head,-1,sizeof(head));
       tot=0;
       int s,t;
       scanf("%d%d",&n,&m);
       int xx=-inf,yy=inf;
       for (int i=1;i<=n;i++)
       {
          int x,y;
          scanf("%d%d",&x,&y);
          if (xx<x) xx=x,t=i;
          if (yy>x) yy=x,s=i;
       }

       while (m--)
       {
          int x,y,c;
          scanf("%d%d%d",&x,&y,&c);
          add(x,y,c);
       }

       printf("%d
",dinic(s,t));
       }
       return 0;
}

于是乎找来Sap 模板：

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
using namespace std;

const int MAXN=100010;//点数的最大值
const int MAXM=400010;//边数的最大值
const int INF=0x3f3f3f3f;

struct Node
{
    int from,to,next;
    int cap;
}edge[MAXM];
int tol;
int head[MAXN];
int dep[MAXN];
int gap[MAXN];//gap[x]=y :说明残留网络中dep[i]==x的个数为y

int n;//n是总的点的个数，包括源点和汇点

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

void add_edge(int u,int v,int w)
{
    edge[tol].from=u;
    edge[tol].to=v;
    edge[tol].cap=w;
    edge[tol].next=head[u];
    head[u]=tol++;
    edge[tol].from=v;
    edge[tol].to=u;
    edge[tol].cap=w;
    edge[tol].next=head[v];
    head[v]=tol++;
}
void BFS(int start,int end)
{
    memset(dep,-1,sizeof(dep));
    memset(gap,0,sizeof(gap));
    gap[0]=1;
    int que[MAXN];
    int front,rear;
    front=rear=0;
    dep[end]=0;
    que[rear++]=end;
    while(front!=rear)
    {
        int u=que[front++];
        if(front==MAXN)front=0;
        for(int i=head[u];i!=-1;i=edge[i].next)
        {
            int v=edge[i].to;
            if(dep[v]!=-1)continue;
            que[rear++]=v;
            if(rear==MAXN)rear=0;
            dep[v]=dep[u]+1;
            ++gap[dep[v]];
        }
    }
}
int SAP(int start,int end)
{
    int res=0;
    BFS(start,end);
    int cur[MAXN];
    int S[MAXN];
    int top=0;
    memcpy(cur,head,sizeof(head));
    int u=start;
    int i;
    while(dep[start]<n)
    {
        if(u==end)
        {
            int temp=INF;
            int inser;
            for(i=0;i<top;i++)
               if(temp>edge[S[i]].cap)
               {
                   temp=edge[S[i]].cap;
                   inser=i;
               }
            for(i=0;i<top;i++)
            {
                edge[S[i]].cap-=temp;
                edge[S[i]^1].cap+=temp;
            }
            res+=temp;
            top=inser;
            u=edge[S[top]].from;
        }
        if(u!=end&&gap[dep[u]-1]==0)//出现断层，无增广路
          break;
        for(i=cur[u];i!=-1;i=edge[i].next)
           if(edge[i].cap!=0&&dep[u]==dep[edge[i].to]+1)
             break;
        if(i!=-1)
        {
            cur[u]=i;
            S[top++]=i;
            u=edge[i].to;
        }
        else
        {
            int min=n;
            for(i=head[u];i!=-1;i=edge[i].next)
            {
                if(edge[i].cap==0)continue;
                if(min>dep[edge[i].to])
                {
                    min=dep[edge[i].to];
                    cur[u]=i;
                }
            }
            --gap[dep[u]];
            dep[u]=min+1;
            ++gap[dep[u]];
            if(u!=start)u=edge[S[--top]].from;
        }
    }
    return res;
}
int main()
{
    int cn;
    int m;
    cin>>cn;
    int t1,t2,t3;
    while(cn--)
    {
        int maxn = -INF;
        int minn = INF;
        int maxi;
        int mini;
        cin>>n>>m;
        init();
        for(int i=1; i<=n; i++)
        {
            scanf("%d %d", &t1, &t2);
            if(maxn < t1)
            {
                maxn = t1;
                maxi = i;
            }
            if(minn > t1)
            {
                minn = t1;
                mini = i;
            }
        }
        while(m--)
        {
            scanf("%d %d %d", &t1, &t2, &t3);
            add_edge(t1, t2, t3);
        }
        printf("%d
", SAP(mini, maxi));
    }
 return 0;
}