func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long int mod = 1e9 + 7;   const int K = 3;   int main() {     long long int t;     cin >> t;     while (t--) {       long long int n;       cin >> n;       long long int ans = -1;       for (int i = 1; i <= n; ++i) {         long long int x;         cin >> x;         ans = max(ans, x - i);       }       cout << ans << endl;     }     return 0;   }   