Cod sursa(job #2960527)

Utilizator adamemi02emanuel adam adamemi02 Data 4 ianuarie 2023 16:29:45
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.46 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream cin("maxflow.in");
ofstream cout("maxflow.out");
int capacity[1001][1001];
int n;
vector<vector<int>>adj;
int bfs(int s,int f,vector<int>&parent){
    for(int j=0;j<parent.size();j++)
        parent[j]=-1;
    queue<pair<int,int>> q;
    parent[s]=-2;
    q.push({s,110001});
    while(!q.empty()){
        int cur=q.front().first;
        int flow=q.front().second;
        q.pop();
        for(auto el:adj[cur]){
            if(parent[el]==-1 && capacity[cur][el]){
                parent[el]=cur;
                int new_flow=min(flow,capacity[cur][el]);
                if(el==f)
                    return new_flow;
                q.push({el,new_flow});
            }
        }
    }
    return 0;
}
int max_flow(int source,int destination){
    int maxflow=0;
    vector<int>parent(n+1);
    int flow;
    while( flow=bfs(source,destination,parent)){

        maxflow+=flow;
        int cur=destination;
        while(cur!=source){
            int prev=parent[cur];
            capacity[cur][prev]+=flow;
            capacity[prev][cur]-=flow;
            cur=prev;
        }
    }
    return maxflow;
}
int main() {
    int m,u,v,c,i;
    ifstream cin("maxflow.in");
    ofstream cout("maxflow.out");
    cin>>n>>m;
    adj.resize(n+1);
    for(i=1;i<=m;i++){
        cin>>u>>v>>c;
        capacity[u][v]=c;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    cout<<max_flow(1,n);

}