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Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 604 Accepted Submission(s): 172
#include <iostream> #include <cstring> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <time.h> #include <string> #include <map> #include <stack> #include <vector> #include <set> #include <queue> #define inf 0x3f3f3f3f #define mod 10000 typedef long long ll; using namespace std; const int N=1005; const int M=10005; struct Node { int v,w; Node(int vv,int ww):v(vv),w(ww){}; }; vector<Node>e[N]; int s,t,n,m,vs,vt; int d[N]; int vis[N]; void spfa() { memset(vis,0,sizeof(vis)); for(int i = 1;i<=n;i++) d[i]=inf; d[s]=0; queue<int>q; q.push(s); while(!q.empty()) { int u = q.front(); q.pop(); vis[u]=0; for(int i = 0;i<e[u].size();i++) { int v = e[u][i].v; if(d[v]>d[u]+1) { d[v]=d[u]+1; if(!vis[v]) q.push(v); vis[v]=1; } } } } struct Edge { int from,to,cap,flow; Edge(int u,int v,int c,int f):from(u),to(v),cap(c),flow(f){} }; struct Dinic { int s,t; vector<Edge>edges; vector<int> G[N]; bool vis[N]; int d[N]; int cur[N]; void init() { for (int i=0;i<=n+1;i++) G[i].clear(); edges.clear(); } void AddEdge(int from,int to,int cap) { edges.push_back(Edge(from,to,cap,0)); edges.push_back(Edge(to,from,0,0)); int mm=edges.size(); G[from].push_back(mm-2); G[to].push_back(mm-1); } bool BFS() { memset(vis,0,sizeof(vis)); queue<int>q; 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; } }dc; int main() { int T; scanf("%d",&T); while(T--) { scanf("%d%d",&n,&m); for(int i = 0;i<=n;i++) e[i].clear(); for(int i = 1;i<=m;i++) { int u,v,di; scanf("%d%d%d",&u,&v,&di); e[u].push_back(Node(v,di)); e[v].push_back(Node(u,di)); } s=1,t=n; spfa(); dc.init(); for(int i = 1;i<=n;i++) for(int j = 0;j<e[i].size();j++) if(d[e[i][j].v]==d[i]+1) dc.AddEdge(i,e[i][j].v,e[i][j].w); printf("%d\n",dc.Maxflow(s,t)); } }
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原文地址:http://www.cnblogs.com/jianrenfang/p/5882589.html