【題解】Codeforces 1323A. Even Subset Sum Problem

#include <iostream>
using namespace std;
 
int t, n, a[105], ans;
 
int main() {
    cin >> t;
    while (t--){
        cin >> n;
        for (int i = 0; i < n; i++){
            cin >> a[i];
        }
        if (n == 1 && a[0] % 2 == 1){
            cout << -1 << "\n";
            continue;
        }
        ans = 0;
        for (int i = 0; i < n; i++){
            if (a[i] % 2 == 0){
                cout << 1 << "\n" << i+1 << "\n";
                break;
            }
            else if (a[i] % 2 != 0){
                if (ans){
                    cout << 2 << "\n" << i << " " << i+1 << "\n";
                    break;
                }
                else ans = i+1;
            }
        }
    }
}