Download Speed

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int INF = 1e18;

vector<vector<int>> capacity;
vector<vector<int>> adj;

int bfs(int s, int t, vector<int>& parent) {
    fill(parent.begin(), parent.end(), -1);
    parent[s] = -2;
    queue<pair<int, int>> q;
    q.push({s, INF});

    while (!q.empty()) {
        int cur = q.front().first;
        int flow = q.front().second;
        q.pop();

        for (int next : adj[cur]) {
            if (parent[next] == -1 && capacity[cur][next] > 0) {
                parent[next] = cur;
                int new_flow = min(flow, capacity[cur][next]);
                if (next == t) {
                    return new_flow;
                }
                q.push({next, new_flow});
            }
        }
    }

    return 0;
}

int edmonds_karp(int s, int t, int n) {
    int flow = 0;
    vector<int> parent(n + 1);

    int new_flow;

    while ((new_flow = bfs(s, t, parent))) {
        flow += new_flow;
        int cur = t;
        while (cur != s) {
            int prev = parent[cur];
            capacity[prev][cur] -= new_flow;
            capacity[cur][prev] += new_flow;
            cur = prev;
        }
    }

    return flow;
}

signed main() {
    int n, m;
    cin >> n >> m;

    capacity.assign(n + 1, vector<int>(n + 1, 0));
    adj.resize(n + 1);

    for (int i = 0; i < m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].push_back(b);
        adj[b].push_back(a);
        capacity[a][b] += c;
    }
    
    cout << edmonds_karp(1, n, n) << endl;

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED