func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   struct node {     int cnt;     node* bit[3];     node() {       bit[0] = bit[1] = NULL;       cnt = 0;     }   };   node* root;   void Insertt(int x) {     node* cur = root;     for (int i = 28; i >= 0; --i) {       if (cur->bit[(x >> i) & 1] == NULL) cur->bit[(x >> i) & 1] = new node();       cur = cur->bit[(x >> i) & 1];       ++(cur->cnt);     }   }   void Erasee(int x) {     node* cur = root;     for (int i = 28; i >= 0; --i) {       --(cur->bit[(x >> i) & 1]->cnt);       if (cur->bit[(x >> i) & 1]->cnt == 0) {         cur->bit[(x >> i) & 1] = NULL;         return;       } else         cur = cur->bit[(x >> i) & 1];     }   }   int Query(int p, int l) {     int res = 0;     node* cur = root;     for (int i = 28; i >= 0; --i) {       if (((l >> i) & 1) == 0) {         if (cur->bit[(p >> i) & 1] != NULL)           cur = cur->bit[(p >> i) & 1];         else           return res;       } else {         if (cur->bit[(p >> i) & 1] != NULL) res += cur->bit[(p >> i) & 1]->cnt;         if (cur->bit[(1 ^ ((p >> i) & 1))] != NULL)           cur = cur->bit[(1 ^ ((p >> i) & 1))];         else           return res;       }     }     return res;   }   int main() {     scanf( %d , &n);     root = new node();     for (int i = 1; i <= n; ++i) {       int type, p, l;       scanf( %d%d , &type, &p);       if (type == 1) Insertt(p);       if (type == 2) Erasee(p);       if (type == 3) {         scanf( %d , &l);         printf( %d n , Query(p, l));       }     }     return 0;   }   