func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 10;   bool lucky[10010];   int n, m;   int a[N];   int t[N + N];   void init() {     memset(lucky, false, sizeof(lucky));     lucky[0] = true;     for (int i = 1; i <= 10000; i++)       if (i % 10 == 4 || i % 10 == 7) lucky[i] = lucky[i / 10];   }   void update(int i, int v) {     if (!v) return;     i += n;     while (i >= 1) {       t[i] += v;       i >>= 1;     }   }   int query(int Left, int Right) {     int res = 0;     Left += n;     Right += n;     while (Left <= Right) {       if (Left % 2) res += t[Left];       if ((~Right) % 2) res += t[Right];       Left = (Left + 1) >> 1;       Right = (Right - 1) >> 1;     }     return res;   }   int main() {     init();     scanf( %d%d , &n, &m);     memset(t, 0, sizeof(t));     for (int i = 0; i < n; i++) {       scanf( %d , &a[i]);       update(i, lucky[a[i]]);     }     char x[10];     int Left, Right, temp;     while (m--) {       scanf( %s , &x);       if (strcmp(x,  count ) == 0) {         scanf( %d%d , &Left, &Right);         Left--;         Right--;         printf( %d n , query(Left, Right));       } else {         scanf( %d%d%d , &Left, &Right, &temp);         Left--;         Right--;         for (int i = Left; i <= Right; i++) {           a[i] += temp;           update(i, lucky[a[i]] - lucky[a[i] - temp]);         }       }     }     return 0;   }   