problem link :- https://mirror.codeforces.com/problemset/problem/1684/C In the given editorial of problem C the code is wrong I think. lets assume that there is a matrix where in which after swapping two colums every row is sorted . but the jth colum will be push_back every time we do it for new row so even if the incorrect columns are 2 there the size of vector bad will increase thus giving the wrong answer. Am i correct please tell me it or wrong if wrong please tell me.

Code in the editorial :-

#include <bits/stdc++.h>

using namespace std;

void solve(vector<vector<int>> &a) {
    int n = a.size(), m = a[0].size();
    vector<int> bad;
    for (int i = 0; i < n && bad.empty(); i++) {
        vector<int> b = a[i];
        sort(b.begin(), b.end());
        for (int j = 0; j < m; j++) {
            if (a[i][j] != b[j]) bad.push_back(j);
        }
    }
    if ((int)bad.size() == 0) {
        cout << 1 << " " << 1 << "\n";
        return;
    }
    if ((int)bad.size() > 2) {
        cout << -1 << "\n";
        return;
    }
    for (int i = 0; i < n; i++) {
        swap(a[i][bad[0]], a[i][bad[1]]);
    }
    for (int i = 0; i < n; i++) {
        for (int j = 1; j < m; j++) {
            if (a[i][j] < a[i][j - 1]) {
                cout << -1 << "\n";
                return;
               }
        }
    }
    cout << bad[0] + 1 << " " << bad[1] + 1 << "\n";
    return;
}

int main() {
    #ifdef LOCAL
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #else
        ios_base::sync_with_stdio(0);
        cin.tie(0);
        cout.tie(0);
    #endif
    int T;
    cin >> T;
    while (T--) {
        int n, m;
        cin >> n >> m;
        vector<vector<int>> a(n, vector<int>(m));
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cin >> a[i][j];
            }
        }
        solve(a);
    }
    return 0;
}