func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = 0x3f3f3f3f;   char dis[2000010];   int a[2000010];   int main() {     int t;     scanf( %d , &t);     for (int i = 0; i < 200010; i += 3) {       dis[i] =  R , dis[i + 1] =  G , dis[i + 2] =  B ;     }     while (t--) {       int n, k;       scanf( %d %d , &n, &k);       string s;       cin >> s;       int minn = INF;       int x = 0;       while (x < 3) {         for (int i = 0; i < n; i++) {           if (s[i] != dis[i + x])             a[i] = 1;           else             a[i] = 0;           if (i != 0) a[i] = a[i - 1] + a[i];         }         x++;         minn = min(minn, a[k - 1]);         for (int i = k; i < n; i++) {           minn = min(minn, a[i] - a[i - k]);         }       }       printf( %d n , minn);     }     return 0;   }   