Pagini recente » Cod sursa (job #506472) | Cod sursa (job #1207848) | Cod sursa (job #1425056) | Cod sursa (job #2685849) | Cod sursa (job #990440)
Cod sursa(job #990440)
#include <fstream>
#include <map>
#include <vector>
#include <queue>
#define uv (v[i].nebs[j])
#define flw (v[i].flow[v[i].nebs[j]])
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
int n,m;
struct node{
vector<int> nebs;
map<int,int> flow;
};
node v[1001];
bool bfs(int parent[],int son[]){
bool ok[1001]={};
queue<int> q;
ok[1]=1;
q.push(1);
while(!q.empty()){
int i=q.front();
q.pop();
for(unsigned j=0;j<v[i].nebs.size();j++){
if(!ok[uv]&&flw>0&&uv!=n){
ok[uv]=1;
parent[uv]=i;
q.push(uv);
}
if(uv==n&&flw>0){
ok[uv]=1;
son[++son[0]]=i;
}
}
}
return ok[n];
}
int main()
{
f>>n>>m;
for(int i=1;i<=m;i++){
int x,y,cs;
f>>x>>y>>cs;
v[x].nebs.push_back(y);
v[x].flow[y]=cs;
v[y].nebs.push_back(x);
v[y].flow[x]=0;
}
int parent[1001],son[1001];
int s=0;
while(bfs(parent,son)){
for(int t=1;t<=son[0];t++){
int i=son[t],j=n;
int flo=v[i].flow[j];
while(i!=1){
j=i;
i=parent[i];
flo=min(flo,v[i].flow[j]);
}
i=son[t],j=n;
v[i].flow[j]-=flo;
v[j].flow[i]+=flo;
while(i!=1){
j=i;
i=parent[i];
v[i].flow[j]-=flo;
v[j].flow[i]+=flo;
}
s+=flo;
}
}
g<<s<<'\n';
return 0;
}