百练+网络流Dinic模版，EK空间使用不够了

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#include <iostream>#include <stdio.h>#include <stdlib.h>#include <algorithm>#include <queue>#include <string.h>#include <vector>#define inf 0x3f3f3f3f#pragma comment(linker, "/STACK:102400000,102400000")using namespace std;const int maxn= 20005;const int maxm=1000005;int N,M;int head[maxn],cur[maxn],cnt;int dist[maxn], vis[maxn];struct node{    int u,v,cap,flow,next;};node edge[maxm];void init(){    cnt =0;    memset(head, -1, sizeof(head));}void add(int u, int v, int w){    node E1={u,v,w,0,head[u]};    edge[cnt]=E1;    head[u]=cnt++;    node E2= {v,u,0,0,head[v]};    edge[cnt] = E2;    head[v]=cnt++;}void getmap(){    int a=0,b=0,w=0;    for(int i=1;i<=N;i++){        scanf("%d %d",&a,&b);        add(0,i,a);        add(i,N+1,b);    }    for(int j=1;j<=M;j++){        scanf("%d %d %d",&a,&b,&w);        add(a,b,w);        add(b,a,w);    }}bool BFS(int s, int t){    queue<int>Q;    memset(vis, 0, sizeof(vis));    memset(dist, -1, sizeof(dist));    dist[s]=0; vis[s]=1;    Q.push(s);    int u=0;    while (!Q.empty()) {        u=Q.front(); Q.pop();        for(int i=head[u];i!=-1;i=edge[i].next){            node E=edge[i];            if(!vis[E.v]&&E.cap>E.flow){                vis[E.v]=1;                dist[E.v]=dist[u]+1;                if(E.v==t) return true;                Q.push(E.v);            }        }    }    return false;}int DFS(int x,int t, int a){    if(x==t || a==0) return a;    int flow=0,f;    for(int& i=cur[x];i!=-1;i=edge[i].next){        node &E=edge[i];        if(dist[E.v]==dist[x]+1&&(f=DFS(E.v,t,min(a,E.cap-E.flow)))>0){            E.flow+=f;            edge[i^1].flow-=f;            flow+=f;            a-=f;            if(a==0) break;        }    }    return flow;}int Maxflow(int s, int t){    int sumflow=0;    while (BFS(s,t)) {        memcpy(cur, head, sizeof(head));        sumflow+=DFS(s,t,inf);    }    return sumflow;}int main(){    scanf("%d %d",&N,&M);    init();    getmap();    printf("%d\n",Maxflow(0, N+1));    return 0;}