func_code_string: #include <bits/stdc++.h>   int main() {     std::vector<int> count(1 << 19);     auto modify = [&](char *s, int dt) {       int len = strlen(s);       std::reverse(s, s + len);       int val = 0;       for (int i = 0; i < 18; ++i) {         val = val | (i >= len ? 0 : (s[i] -  0  & 1)) << i;       }       count[val] += dt;     };     auto query = [&](char *s) {       int len = strlen(s);       std::reverse(s, s + len);       int val = 0;       for (int i = 0; s[i]; ++i) {         val |= s[i] -  0  << i;       }       return count[val];     };     int t;     scanf( %d , &t);     for (int _ = 0; _ < t; ++_) {       char op[2];       char str[18 + 1];       scanf( %s%s , op, str);       if (op[0] ==  + ) {         modify(str, 1);       } else if (op[0] ==  - ) {         modify(str, -1);       } else {         printf( %d n , query(str));       }     }   }   