poj3461

来源：互联网发布：vulcan软件编辑：程序博客网时间：2024/05/29 16:06

题目还没看：看了翻译版的
虽然学习了KMP，但是面对输入字符串，以及如何计算字符串的长度，我还表示头疼，现在终于可以解决啦

#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int N = 1000002;const int M = 10002;int P[M], Count = 0;void Next(char *t, int m){    int j = 0;    P[1] = 0;    for (int i = 2; i <= m; i++)    {        while (j>0 && t[j + 1] != t[i])            j = P[j];        if (t[i] == t[j + 1])            j++;        P[i] = j;    }}void KMP(char *t, char *s, int m, int n){    P[0] = 0;    int j = 0;    for (int i = 1; i <= n; i++)    {        while (j>0 && s[i] != t[j + 1])            j = P[j];        if (s[i] == t[j + 1])            j++;        if (j == m)        {            Count++;            j = P[j];        }    }}int main(){    int n, m, k;    scanf("%d", &n);    char s[N], t[M];    while (n--)    {        Count = 0;//每次要重新计数，都死在这里        memset(P,0,sizeof(P));        scanf("%s%s", t + 1, s + 1);        int m = strlen(t + 1);//输入字符串        int k = strlen(s + 1);        Next(t, m);        KMP(t, s, m, k);        printf("%d\n", Count);    }    return 0;}

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