二维矩阵匹配+hash模板

二维矩阵匹配+hash模板

#include <algorithm>
#include <cstring>
#include <set>
using namespace std;
typedef unsigned long long  ull;
const int MAX_SIZE = 1010;
const int MAX_T = 110;

int N,M,T,P,Q;
char field[MAX_SIZE][MAX_SIZE];
char patterns[MAX_T][MAX_SIZE][MAX_SIZE];
ull has[MAX_SIZE][MAX_SIZE],tmp[MAX_SIZE][MAX_SIZE];
int cas;

void (char a[MAX_SIZE][MAX_SIZE],int n, int m)
{
    const ull B1 = 9973;
    const ull B2 = 100000007;
    ull t1 = 1;
    for(int i = 0; i < Q; ++i) t1 *= B1;
    for(int i = 0; i < n; ++i){//先把矩阵每行 看成一串字符串进行hash压缩
        ull e = 0;
        for(int j = 0; j < Q; ++j) e = e * B1 + a[i][j];
        for(int j = 0; j + Q <= m; ++j){//滚动hash
            tmp[i][j] = e;
            if(j + Q < m)
                e = e * B1 - t1 * a[i][j] + a[i][j + Q];
        }
    }
    ull t2 = 1;
    for(int i = 0; i < P; ++i) t2 *= B2;//在把上面压缩的进行列hash
    for(int j = 0; j + Q <= m; ++j){
        ull e = 0;
        for(int i = 0; i < P; ++i) e = e * B2 + tmp[i][j];
        for(int i = 0; i + P <= n; ++i){
            has[i][j] = e;
            if(i + P < n) e = e * B2 - t2 * tmp[i][j] + tmp[i+P][j];
        }
    }
}

void solve()
{
    multiset<ull> unseen;//用multiset 进行统计
    for(int k = 0; k < T; ++k){
        compute_hash(patterns[k],P,Q);
        unseen.insert(has[0][0]);
    }
    compute_hash(field,N,M);
    for(int i = 0; i + P <= N; i++)
        for(int j = 0; j + Q <= M; j++)
            unseen.erase(has[i][j]);
    int ans=T-unseen.size();
    printf("Case %d: %dn",++cas ,ans);
}

int main(void)
{
    while(scanf("%d%d%d%d%d",&N,&M,&T,&P,&Q) && (N+M+T+P+Q)){
        for(int i = 0; i < N; i++)
            scanf("%s",field[i]);
        for(int i = 0; i < T; i++)
		{
            for(int j = 0; j < P; j++)
                scanf("%s",patterns[i][j]);
        }
        solve();
    }
    return 0;
}