3SUM

input/code.cpp: In function 'll maxflow(ll, ll)':
input/code.cpp:43:21: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   43 |     while (new_flow = bfs(s, t, parent)) {
      |            ~~~~~~~~~^~~~~~~~~~~~~~~~~~~

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <queue>
#include <climits>
#include <set>
using namespace std;
typedef long long ll;
ll n;
vector<vector<ll>> capacity;
vector<vector<ll>> adj;

ll bfs(ll s, ll t, vector<ll>& parent) {
    fill(parent.begin(), parent.end(), -1);
    parent[s] = -2;
    queue<pair<ll, ll>> q;
    q.push({s, LLONG_MAX});
    
    while (!q.empty()) {
        ll cur = q.front().first;
        ll flow = q.front().second;
        q.pop();
        
        for (ll next : adj[cur]) {
            if (parent[next] == -1 && capacity[cur][next]) {
                parent[next] = cur;
                ll new_flow = min(flow, capacity[cur][next]);
                if (next == t) return new_flow;
                q.push({next, new_flow});
            }
        }
    }
    
    return 0;
}

ll maxflow(ll s, ll t) {
    ll flow = 0;
    vector<ll> parent(n + 1);
    ll new_flow;
    
    while (new_flow = bfs(s, t, parent)) {
        flow += new_flow;
        ll cur = t;
        while (cur != s) {
            ll prev = parent[cur];
            capacity[prev][cur] -= new_flow;
            capacity[cur][prev] += new_flow;
            cur = prev;
        }
    }
    
    return flow;
}

struct node{
    ll index;
    ll value;

};

bool compare(const node &a, const node &b){
    return a.value < b.value;
}

void task1(){
    ll s, t;
    cin >> s >> t;
    vector<node> ints(s + 1);
    vector<ll> ints2(s + 1);
    multiset<ll> mp;

    for(ll i = 1; i <= s; i++){
        ll x;
        cin >> x;
        node n = { i, x };
        ints[i] = n;
       // ints[i] = x;
        ints2[i] = x;
        //mp.insert(x);
    } 

    vector<ll> temp;
    sort(ints.begin(), ints.end(), compare);
    int left = 1, right = s;
    for(int i = 1; i <= s; i++){
        while(left < right){
            ll sum = ints[left].value + ints[right].value + ints[i].value;
            if(sum == t && left != i && right != i){
                std::cout << ints[left].index << " " << ints[right].index << " " << ints[i].index << endl;
                
                return;
            }
            if(sum < t) left++;
            else right--;
        }
    }

    //int dummy = 0;
    std::cout << "IMPOSSIBLE" << endl;
}

void task2(){
     ll m;
    cin >> n >> m;
    capacity.assign(n + 1, vector<ll>(n + 1, 0));
    adj.assign(n + 1, vector<ll>());
    
    for (ll i = 0; i < m; i++) {
        ll a, b, c;
        cin >> a >> b >> c;
        capacity[a][b] += c;
        adj[a].push_back(b);
    }
}


int main() {
   task1();
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: ACCEPTED

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: ACCEPTED

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED