func_code_string: #include <bits/stdc++.h>   #pragma comment(linker,  /STACK:1024000000,1024000000 )   using namespace std;   const long long inf = 0x3f3f3f3f3f3f3f3f;   const int maxn = 100005;   int main() {     int n;     long long r;     scanf( %d %lld , &n, &r);     n = 1 << n;     int c[n];     double sum = 0;     for (int i = 0; i < n; i++) scanf( %d , &c[i]), sum += c[i];     printf( %.6f n , sum / n);     for (int i = 0; i < r; i++) {       int z, g;       scanf( %d %d , &z, &g);       sum = sum - c[z] + g;       c[z] = g;       printf( %.6f n , sum / n);     }   }   