HDU 3549 Flow Problem（网络流模板题）

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记录一下模板
#include <vector>#include <cstring>#include <algorithm>#include <cstdio>#include <queue>using namespace std;#define maxn 1100#define INF 0x7f7f7f7fstruct Edge {    int from,to,cap,flow;};struct  Dinic {    int n,m,s,t;    vector<Edge>edges;    vector<int>G[maxn];    bool vis[maxn];    int d[maxn];    int cur[maxn];    void addEdge(int from,int to,int cap) {    edges.push_back((Edge) {from,to,cap,0});    edges.push_back((Edge) {to,from,0,0});    m=edges.size();    G[from].push_back(m-2);    G[to].push_back(m-1);    }    void init(){      edges.clear();      for(int i=1;i<=maxn;i++) G[i].clear();    }    bool Bfs() {        memset(vis,0,sizeof(vis));        queue<int>Q;        while(!Q.empty()) Q.pop();        Q.push(s);        d[s]=0;        vis[s] = 1;        while(!Q.empty()) {            int x = Q.front();            Q.pop();            for(int i=0; i<G[x].size(); i++) {                Edge& e = edges[G[x][i]];                if(!vis[e.to]&&e.cap>e.flow) {                    vis[e.to] = 1;                    d[e.to] = d[x]+1;                    Q.push(e.to);                }            }        }        return vis[t];    }    int dfs(int x,int a) {        if(x==t||a==0) return a;        int flow = 0,f;        for(int &i=cur[x]; i<G[x].size(); i++) {            Edge& e  = edges[G[x][i]];            if(d[x]+1==d[e.to]&&(f=dfs(e.to,min(a,e.cap-e.flow)))>0) {                e.flow += f;                edges[G[x][i]^1].flow -= f;                flow += f;                a -= f;                if(a==0) break;            }        }        return flow;    }    int maxflow(int s,int t) {        this->s=s;        this->t=t;        int flow  = 0;        while(Bfs()) {            memset(cur,0,sizeof(cur));            flow+=dfs(s,INF);        }        return flow;    }};int main(){    int T;    int n,k;    Dinic slove;    while(scanf("%d",&T)==1){    int cas=0;    while(T--){        scanf("%d%d",&n,&k);        slove.init();        while(k--){            int x,y,z;            scanf("%d%d%d",&x,&y,&z);            slove.addEdge(x,y,z);        }        printf("Case %d: %d\n",++cas,slove.maxflow(1,n));    }    }}
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