func_code_string: #include <bits/stdc++.h>   using namespace std;   int getMin(int l, int r, char a[], char ch) {     int count = 0;     for (int i = l; i <= r; i++) {       if (a[i] != ch) {         count++;       }     }     return count;   }   int findans(int l, int r, char a[], char ch) {     if (l == r) {       if (a[l] == ch) {         return 0;       } else {         return 1;       }     }     int mid = (l + r) / 2;     return min(getMin(l, mid, a, ch) + findans(mid + 1, r, a, ch + 1),                getMin(mid + 1, r, a, ch) + findans(l, mid, a, ch + 1));   }   int main() {     long long int t;     cin >> t;     while (t--) {       long long int n;       cin >> n;       char a[n];       for (int i = 0; i < n; i++) {         cin >> a[i];       }       int ans = findans(0, n - 1, a,  a );       cout << ans << endl;     }   }   