POJ 3690 Constellations (哈希)
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题意:给定上一n*m的矩阵,然后的t个p*q的小矩阵,问你匹配不上的有多少个。
析:可以直接用哈希,也可以用AC自动机解决。
代码如下:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #include <sstream> #define debug() puts("++++"); #define gcd(a, b) __gcd(a, b) #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef unsigned long long ULL; typedef pair<int, int> P; const int INF = 0x3f3f3f3f; const LL LNF = 1e16; const double inf = 0x3f3f3f3f3f3f; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 1000 + 10; const int mod = 1e9 + 7; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, 1, 0, -1}; const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline bool is_in(int r, int c){ return r >= 0 && r < n && c >= 0 && c < m; } int p, q; const ULL B1 = 123; const ULL B2 = 9973; char s[maxn][maxn], ch[maxn][maxn]; ULL Hash[maxn][maxn], tmp[maxn][maxn]; ULL t1, t2; void solve(char s[][maxn], int n, int m){ for(int i = 0; i < n; ++i){ ULL e = 0; for(int j = 0; j < q; ++j) e = e * B1 + s[i][j]; for(int j = 0; j + q <= m; ++j){ tmp[i][j] = e; if(j + q < m) e = e * B1 - t1 * s[i][j] + s[i][j+q]; } } 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){ Hash[i][j] = e; if(i + p < n) e = e * B2 - t2 * tmp[i][j] + tmp[i+p][j]; } } } int main(){ int t, kase = 0; while(scanf("%d %d %d %d %d", &n, &m, &t, &p, &q) == 5 && n+m+p+q+t){ for(int i = 0; i < n; ++i) scanf("%s", s+i); multiset<ULL> sets; t1 = t2 = 1; for(int i = 0; i < q; ++i) t1 *= B1; for(int i = 0; i < p; ++i) t2 *= B2; for(int i = 0; i < t; ++i){ for(int j = 0; j < p; ++j) scanf("%s", ch+j); solve(ch, p, q); sets.insert(Hash[0][0]); } solve(s, n, m); for(int i = 0; i + p <= n; ++i) for(int j = 0; j + q <= m; ++j) sets.erase(Hash[i][j]); printf("Case %d: %d\n", ++kase, t-(int)sets.size()); } return 0; }
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