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#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> llPair;

vector<vector<llPair>> adj;  // to, capacity
vector<bool> been;
int sink;

ll dfs(int node, ll cap) {
    if (been[node]) return 0;
    if (cap == 0) return 0;
    if (node == sink) return cap;
    been[node] = true;
    
    for (auto& v: adj[node]) {
        ll newCap = cap;
        if (newCap == -1) { newCap = v.second; }
        else if (v.second <= 0) { continue; }
        else { newCap = min(newCap, v.second); }
        if (newCap <= 0) continue;
        ll res = dfs(v.first, newCap);
        if (res <= 0) continue;
        v.second -= res;
        for (auto& u: adj[v.first]) {
            if (u.first == node) {
                u.second += res;
                break;
            }
        }
        return res;
    }

    return 0;
}

int main() {
    int n, m;
    cin >> n >> m;
    sink = n-1;

    adj.resize(n);
    been.resize(n);

    int a, b, c;
    for (int i=0; i<m; i++) {
        cin >> a >> b >> c;
        a--; b--;
        adj[a].push_back(llPair(b, c));
        adj[b].push_back(llPair(a, 0));
    }

    ll total = 0;
    while (true) {
        for (int i=0; i<n; i++) { been[i] = false; }
        ll res = dfs(0, -1);
        if (res <= 0) break;
        total += res;
    }
    cout << total << 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