Pagini recente » Cod sursa (job #2485434) | Cod sursa (job #1310901) | Cod sursa (job #840261) | Cod sursa (job #1102819) | Cod sursa (job #2697704)
#include <fstream>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
ifstream cin ("maxflow.in");
ofstream cout ("maxflow.out");
queue <int> q;
vector <int> v[1005], aux;
int c[1005][1005];
int anterior[1005], cost[1005];
int ans, n, m;
bool ok = true;
void reinit() {
memset(anterior, 0, sizeof(anterior));
memset(cost, 0, sizeof(cost));
cost[1] = 2e9;
while (!q.empty())
q.pop();
ok = false;
aux.clear();
}
void bfs();
void reconstituire(int x) {
int nod = x;
cost[n] = min(cost[x], c[x][n]);
if (cost[n] == 0)
return;
while (nod != 1) {
if (c[anterior[nod]][nod] < cost[n])
cost[n] = c[anterior[nod]][nod];
nod = anterior[nod];
}
if(cost[n] == 0)
return;
c[x][n] -= cost[n];
c[n][x] += cost[n];
nod = x;
while (nod != 1) {
c[anterior[nod]][nod] -= cost[n];
c[nod][anterior[nod]] += cost[n];
nod = anterior[nod];
}
ok = true;
ans += cost[n];
}
void bfs() {
reinit();
q.push(1);
while (!q.empty()) {
int nod = q.front();
q.pop();
if (c[nod][n] > 0) {
aux.push_back(nod);
}
for (auto it : v[nod]) {
if (c[nod][it] == 0 || cost[it] || it == n)
continue;
cost[it] = min(cost[nod], c[nod][it]);
anterior[it] = nod;
q.push(it);
}
}
}
int main() {
cin >> n >> m;
int x, y, z;
for (int i = 1; i <= m; ++i) {
cin >> x >> y >> z;
c[x][y] = z;
v[x].push_back(y);
v[y].push_back(x);
}
while(ok) {
bfs();
for (auto it : aux) {
reconstituire(it);
}
}
cout << ans;
return 0;
}