3SUM

#include<vector>
#include<iostream>
#include<algorithm>
using namespace std;


bool SSSum(vector<int>&v, int x){
    int n = v.size();
    sort(v.begin(), v.end());
    for (int i = 0; i < n - 2; i++) {
        int l = i +1;
        int r = n -1;
        while (l != r) {
            int sum = v[i] + v[l] + v[r];
            if (sum == x) {
                cout << v[i] << " "<< v[l] << " " << v[r];
                return true;
            } 
            else if (sum < x)
                l++;
            else
                r--;
        }
    }
    return false;
}
int main(){
    int n,x;
    cin >> n >> x;

    vector<int> v(n);
    for(int i = 0; i < n; ++i){
        cin >> v[i];
    }
    if(not SSSum(v,x))
        cout<<"IMPOSSIBLE"<<endl;

}

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: WRONG ANSWER

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: WRONG ANSWER

Test 19

Verdict: ACCEPTED

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED