Bzoj 2462 Beijing 2011 Matrix template Two-dimensional hash

The main topic: Give a m*n 01 matrix, the following Q queries, the query matrix exists in the size of the K*l sub-matrix.

Idea: two-dimensional hash. We first hash the big matrix and then insert all the possible k*l sub-matrices into the hash table, and then just look at the hash tables for each query hash to see if they exist.

It is worth mentioning that the problem only requires the output of 10 1 can be AC.

CODE:

#include <cstdio> #include <bitset> #include <cstring> #include <iostream> #include < Algorithm> #define MAX 1100using namespace std;const unsigned int BASE1 = 10016957;const unsigned int BASE2 = 10016957;c onst int MO = 99999997; int m,n,ask_m,ask_n,asks;unsigned int hash[max][max],_hash[max][max];unsigned int Pow1[max],pow2[max]; BOOL set[100000000];            inline unsigned int gethash () {for (int i = 1, i <= ask_m; ++i) for (int j = 1; j <= Ask_n; ++j)    _HASH[I][J] + = _hash[i-1][j] * BASE1; for (int i = 1, i <= ask_m; ++i) for (int j = 1; j <= ask_n; ++j) _hash[i][j] + = _hash[i][j-1] * B    ASE2; return _hash[ask_m][ask_n];}    int main () {cin >> m >> n >> ask_m >> ask_n;    for (int i = 1; I <= m; ++i) for (int j = 1; j <= N; ++j) scanf ("%1d", &hash[i][j]);    Pow1[0] = pow2[0] = 1; for (int i = 1; i <=; ++i) pow1[i] = pow1[i-1] * Base1,pow2[i] = Pow2[I-1] * BASE2;    for (int i = 1, i <= m; ++i) for (int j = 1; j <= N; ++j) hash[i][j] + = hash[i-1][j] * BASE1;    for (int i = 1, i <= m; ++i) for (int j = 1; j <= N; ++j) hash[i][j] + = hash[i][j-1] * BASE2;            for (int i = ask_m, I <= m; ++i) for (int j = ask_n; J <= N; ++j) {unsigned int h = hash[i][j];            H-= hash[i-ask_m][j] * Pow1[ask_m];            H-= hash[i][j-ask_n] * Pow2[ask_n];            H + = hash[i-ask_m][j-ask_n] * pow1[ask_m] * Pow2[ask_n];        Set[h% MO] = true; } for (Cin >> asks; asks--;) {for (int i = 1, i <= ask_m; ++i) for (int j = 1; j <= ask_n; ++j) scanf ("%1d",&        _HASH[I][J]); Puts (Set[gethash ()% MO]?    "1": "0"); } return 0;}

Bzoj 2462 Beijing 2011 Matrix template Two-dimensional hash