func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long int a, b, c, co, i, j, k, l, m, n;     cin >> n;     co = 0;     set<long long int> myset;     for (i = 0; i < n; i++) {       cin >> a;       myset.insert(a);     }     if (myset.size() > 3)       cout <<  NO n ;     else if (myset.size() == 3) {       i = 0;       for (auto it = myset.begin(); it != myset.end(); it++) {         if (i == 0) a = *it;         if (i == 1) b = *it;         if (i == 2) c = *it;         i++;       }       if (abs(a - b) == abs(b - c))         cout <<  YES n ;       else         cout <<  NO n ;     } else       cout <<  YES n ;     return 0;   }   