answer.code: In function ‘int main()’:
answer.code:13:9: error: ‘ans’ was not declared in this scope
   13 |         ans = 0;
      |         ^~~
answer.code:20:38: warning: extended initializer lists only available with ‘-std=c++11’ or ‘-std=gnu++11’
   20 |                         ve.push_back({i,a[i] - a[n]});
      |                                      ^
answer.code:20:37: warning: extended initializer lists only available with ‘-std=c++11’ or ‘-std=gnu++11’
   20 |                         ve.push_back({i,a[i] - a[n]});
      |                         ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~