Dinic Template

#include<cstdio>#include<cstdlib>#include<cstring>#include<queue>#include<vector>#include<algorithm>#include<cmath>using namespace std;#define INF 0x7f7f7f7f#define maxn 10000 + 10struct Edge {  int from, to, cap, flow;  Edge(int u, int v, int c,int f):from(u), to(v), cap(c), flow(f){}};bool operator < (const Edge& a, const Edge& b) {  return a.from < b.from || (a.from == b.from && a.to < b.to);}struct Dinic {int n,m,s,t;vector<Edge> edges;vector<int> gr[maxn];          int d[maxn], cur[maxn]; bool vis[maxn]; inline void ClearAll(int n) {    for(int i = 0; i < n; i++) gr[i].clear();    edges.clear();}inline void ClearFlow() {    for(int i = 0; i < edges.size(); i++) edges[i].flow = 0;    }inline 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();    gr[from].push_back(m-2);    gr[to].push_back(m-1);}inline bool BFS() {    memset(vis, 0, sizeof(vis));    queue<int> que;    que.push(s);    vis[s] = 1;    d[s] = 0;    while(!que.empty()) {      int x = que.front(); que.pop();      for(int i = 0; i < gr[x].size(); i++) {        Edge& e = edges[gr[x][i]];        if(!vis[e.to] && e.cap > e.flow) {          vis[e.to] = 1;          d[e.to] = d[x] + 1;          que.push(e.to);        }      }    }    return vis[t];}inline int DFS(int x, int a) {    if(x == t || a == 0) return a;    int flow = 0, f;    for(int& i = cur[x]; i < gr[x].size(); i++) {      Edge& e = edges[gr[x][i]];      if(d[x] + 1 == d[e.to] && (f = DFS(e.to, min(a, e.cap-e.flow))) > 0) {        e.flow += f;        edges[gr[x][i]^1].flow -= f;        flow += f;        a -= f;        if(a == 0) break;      }    }    return flow;}inline 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;}inline vector<int> Mincut() { // call this after maxflow    vector<int> ans;    for(int i = 0; i < edges.size(); i++) {      Edge& e = edges[i];      if(vis[e.from] && !vis[e.to] && e.cap > 0) ans.push_back(i);    }    return ans;}}g;int main() {//freopen("dinic.in","r",stdin);//freopen("dinic.out","w",stdout);  int np,mp,sp,tp; scanf("%d%d%d%d",&np,&mp,&sp,&tp);  g.ClearAll(np);  while(mp --){ int u,v,c;scanf("%d%d%d",&u,&v,&c); g.AddEdge(u,v,c);  }  int flow = g.Maxflow(sp,tp);  printf("%d\n",flow);  //fclose(stdin);  //fclose(stdout); return 0;}