题解 | #小灯做题#

#include<bits/stdc++.h>
using namespace std;

int main() {
  int t;
  cin >> t;
  
  while (t--) {
    int a, b, c, k;
    cin >> a >> b >> c >> k;
    
    if (a == k || b == k || c == k) {
      cout << 0 << '\n';
      continue;
    }
    
    // 目标值大于2则无法到达
    if (k > 2) {
      cout << -1 << '\n';
      continue;
    }
    
    int n = 0;
    if (a == 0 || b == 0 || c == 0) n++;
    // 只有当k > 1时，abc中的1才能为答案做贡献
    if (k > 1 && (a == 1 || b == 1 || c == 1)) n++;

    cout << k - n + 1 << '\n';
  }
}