Download Speed

input/code.cpp: In function 'long long int maxflow(long long int, long long int)':
input/code.cpp:70:21: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   70 |     while (new_flow = bfs(s, t, parent)) {
      |            ~~~~~~~~~^~~~~~~~~~~~~~~~~~~

#include <bits/stdc++.h>
 
using namespace std;
#define int long long
#define vout(x) for(int i=0;i<(long long)x.size();i++) printf("%lld ",x[i]);
 
// g++ <filename>.cpp -g -Wall -Wextra -DDEBUG -o <executable>
 
// copied from: https://codeforces.com/blog/entry/79024
// === Debug macro starts here ===
 
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x) {++recur_depth; auto x_=x; --recur_depth; cerr<<string(recur_depth, '\t')<<"\e[91m"<<__func__<<":"<<__LINE__<<"\t"<<#x<<" = "<<x_<<"\e[39m"<<endl;}
#else
#define dbg(x)
#endif
template<typename Ostream, typename Cont>
typename enable_if<is_same<Ostream,ostream>::value, Ostream&>::type operator<<(Ostream& os,  const Cont& v){
	os<<"[";
	for(auto& x:v){os<<x<<", ";}
	return os<<"]";
}
template<typename Ostream, typename ...Ts>
Ostream& operator<<(Ostream& os,  const pair<Ts...>& p){
	return os<<"{"<<p.first<<", "<<p.second<<"}";
}
 
// === Debug macro ends here ===
 
const int INF = LONG_MAX;
 
int n, m;
vector<vector<int>> capacity;
vector<vector<int>> adj;
 
// code taken and adapted from https://cp-algorithms.com/graph/edmonds_karp.html
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]) {
                parent[next] = cur;
                int new_flow = min(flow, capacity[cur][next]);
                if (next == t) 
                    return new_flow;
                q.push({next, new_flow});
            }
        }
    }
    return 0;
}
 
// code taken and adapted from https://cp-algorithms.com/graph/edmonds_karp.html
int maxflow(int s, int t) {
 
    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() {
 
    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;
        capacity[a][b] += c;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
 
    int source = 1;
    int sink = n;
    cout << maxflow(source, sink) << "\n";
 
    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