Cod sursa(job #2342071)

Utilizator mateibanuBanu Matei Costin mateibanu Data 12 februarie 2019 16:21:08
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.83 kb
#include <bits/stdc++.h>

using namespace std;

int c[1002][1002],f[1002][1002],t[1002];
vector<int>v[1002];
int n,r,m;
/*
int BF(){

    int nr,i,nod,vec;

    queue<int>q;

    memset(t,0,sizeof(t));

    t[1]=-1;

    q.push(1);

    while (!q.empty()){

        nod=q.front();

        q.pop();

        nr=v[nod].size();

        for (i=0;i<nr;i++){

            vec=v[nod][i];

            if (t[vec]||c[nod][vec]==f[nod][vec]) continue;

            t[vec]=nod;

            q.push(vec);

            if (vec==n) return 1;

        }

    }

    return 0;

}
*/


int bf(){
    int o,vec,nr,i;
    queue<int>q;
    q.push(1);
    memset(t,0,sizeof(t));
    t[1]=-1;
    while (!q.empty()){
        o=q.front();
        q.pop();
        nr=v[o].size();
        for (i=0;i<nr;i++){
            vec=v[o][i];
            if (t[vec]||c[o][vec]==f[o][vec]) continue;
            q.push(vec);
            t[vec]=o;
            if (vec==n) return 1;
        }
    }
    return 0;
}

int main()
{
    freopen("maxflow.in","r",stdin);
    freopen("maxflow.out","w",stdout);
    int i,x,y,z,j,dif;
    scanf("%d%d",&n,&m);
    for (i=1;i<=m;i++){
        scanf("%d%d%d",&x,&y,&z);
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y]=z;
    }
    while (bf()){
        for (i=1;i<=n;i++){
            if (c[i][n]==f[i][n]||!t[i]) continue;
            dif=c[i][n]-f[i][n];
            j=i;
            for (j=i;j>1;j=t[j]){
                dif=min(dif,c[t[j]][j]-f[t[j]][j]);
            }
            if (dif==0) continue;
            f[i][n]+=dif;
            f[n][i]-=dif;
            for (j=i;j>1;j=t[j]){
                f[t[j]][j]+=dif;
                f[j][t[j]]-=dif;
            }
            r+=dif;
        }
    }
    printf("%d",r);
    return 0;
}