func_code_string: /*    * @Descripttion:     * @version:     * @Author: 纸月二五    * @Date: 2021-05-11 17:50:44    */   #include<bits/stdc++.h>   using namespace std;      int num[200010];      long long cal(long long m)   {       return m * (m - 1) / 2;   }      int main()   {       int T;       scanf( %d ,&T);          while(T --)       {           int n;           scanf( %d ,&n);           for(int i = 1;i <= n;i ++)           {               scanf( %d ,&num[i]);               num[i] = num[i] - i;           }              sort(num + 1,num + 1 + n);              long long sum = 0;           int last = num[1];           long long ans = 0;           for(int i = 1;i <= n;i ++)           {               if(num[i] == last)               {                   sum ++;                   if(i == n)                   ans += cal(sum);               }               else               {                   ans += cal(sum);                   sum = 1;                   last = num[i];               }           }           printf( %lld n ,ans);       }       //system( pause );       return 0;   }