Mai intai trebuie sa te autentifici.
Cod sursa(job #3041318)
Utilizator | Data | 31 martie 2023 11:37:56 | |
---|---|---|---|
Problema | Flux maxim | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 1.61 kb |
#include <fstream>
#include <queue>
#include <bitset>
using namespace std;
ifstream cin("maxflow.in");
ofstream cout("maxflow.out");
const int NMAX = 1e3;
const int inf = 2e9;
int flux[NMAX + 1][NMAX + 1], t[NMAX + 1];
vector <int> g[NMAX + 1], rg[NMAX + 1];
bitset <NMAX + 1> viz;
bool bfs(int x, int n){
viz = 0;
viz[x] = 1;
queue <int> q;
q.push(x);
while(!q.empty()){
int x = q.front();
q.pop();
if(x == n)
return true;
for(auto y : g[x]){
if(viz[y] == 1 || flux[x][y] <= 0)
continue;
t[y] = x;
viz[y] = 1;
q.push(y);
}
}
return false;
}
int main(){
int n = 0, m = 0;
cin >> n >> m;
for(int i = 0; i < m; i++){
int x = 0, y = 0, capacitate = 0;
cin >> x >> y >> capacitate;
flux[x][y] = capacitate;
g[x].push_back(y);
g[y].push_back(x);
}
long long maxi = 0;
while(bfs(1, n)){
for(auto y : g[n]){
if(viz[y] == 0 || flux[y][n] <= 0)
continue;
int mini = inf;
t[n] = y;
int x = n;
while(x != 1){
mini = min(mini, flux[t[x]][x]);
x = t[x];
}
if(mini == 0)
continue;
maxi += mini;
x = n;
while(x != 1){
flux[x][t[x]] += mini;
flux[t[x]][x] -= mini;
x = t[x];
}
}
}
cout << maxi;
cin.close();
cout.close();
return 0;
}