Pagini recente » Cod sursa (job #650591) | Cod sursa (job #1248986) | Cod sursa (job #1341635) | Cod sursa (job #2552653) | Cod sursa (job #2778870)
#include <bits/stdc++.h>
using namespace std;
class flow {
public:
struct edge {
int to;
int cap;
};
int n;
vector<edge> edges;
vector<vector<int>> g;
vector<int> level, pos;
flow(int nn) : n(nn), g(n + 1), level(n + 1), pos(n + 1) {
}
void add(int a, int b, int c) {
g[a].push_back((int) edges.size());
g[b].push_back((int) edges.size() + 1);
edges.push_back({b, c});
edges.push_back({a, 0});
}
int dfs(int a, int cur) {
if (a == n || !cur) return cur;
while (pos[a] < (int) g[a].size()) {
int i = g[a][pos[a]++];
int b = edges[i].to, cap = edges[i].cap;
if (level[b] == 1 + level[a] && cap > 0) {
int x = dfs(b, min(cur, cap));
if (x > 0) {
edges[i].cap -= x;
edges[i ^ 1].cap += x;
return x;
}
}
}
return 0;
}
int get() {
int sol = 0;
while (1) {
for (int i = 1; i <= n; i++) {
level[i] = -1;
pos[i] = 0;
}
level[1] = 0;
queue<int> q;
q.push(1);
while (!q.empty()) {
int a = q.front();
q.pop();
for (auto &i : g[a]) {
int b = edges[i].to;
if (edges[i].cap && level[b] == -1) {
level[b] = 1 + level[a];
q.push(b);
}
}
}
if (level[n] == -1) break;
while (1) {
int nw = dfs(1, (int) 1e9);
if (nw == 0) break;
sol += nw;
}
}
return sol;
}
};
const int N = 1000 + 7;
int n, m;
int main() {
freopen ("maxflow.in", "r", stdin), freopen ("maxflow.out", "w", stdout);
/// freopen ("input", "r", stdin);
cin >> n >> m;
flow f(n);
for (int i = 1; i <= m; i++) {
int a, b, c;
cin >> a >> b >> c;
f.add(a, b, c);
}
cout << f.get() << "\n";
return 0;
}