Excel Sheet Column Title Problem & Solution

#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops")

static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();

class Solution {
public:
  string convertToTitle(int columnNumber) {
    string result;

    while (columnNumber > 0) {

      // Must take into account the offset of the column number.
      --columnNumber;

      result += columnNumber % 26 + 'A';
      columnNumber /= 26;
    }

    reverse(result.begin(), result.end());

    return result;
  }
};