HDU 2594 KMP
#include <cstdio> #include <cstdlib> #include <cstring> #include <cmath> #include <cctype> #include <vector> #include <stack> #include <queue> #include <map> #include <algorithm> #include <iostream> #include <string> #include <set> #define X first #define Y second #define sqr(x) (x)*(x) #pragma comment(linker,"/STACK:102400000,102400000") using namespace std; const double PI = acos(-1.0); map<int, int>::iterator it; typedef long long LL ; template<typename T> void checkmin(T &x, T y) {x = min(x, y);} template<typename T> void checkmax(T &x, T y) {x = max(x, y);} const int N = 100005; int p[N]; int KMP(char *a, int n, char *b, int m) { p[0] = -1; int i, j = -1; for(i = 1; i <= m; i++) { while((j > -1) && (b[j+1] != b[i])) j = p[j]; if(b[j+1] == b[i]) j++; p[i] = j; } //for(i=0;i<m;i++) printf("%d ",p[i]); printf("\n"); j = -1; for(i = 0; i < n; i++) { while((j > -1) && (b[j+1] != a[i])) j = p[j]; if(b[j+1] == a[i]) { j++; } if(j == m - 1) { //printf("i=%d\n",i); //return i-m+1; j = p[j]; } } return -1; } char s[N], t[N]; int main() { while(~scanf("%s%s", s, t)) { int m = min(strlen(s),strlen(t)); strcat(s,t); int n = strlen(s); KMP(s, n, s, n); int res = min(p[n-1]+1,m); if(res) { for(int i = 0; i < res; ++i) { printf("%c", s[i]); } printf(" %d\n",res); } else { puts("0"); } } return 0; }