hiho1015(kmp+统计出现次数）

http://hihocoder.com/problemset/problem/1015

时隔多天再次温习了一下KMP

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;
 int Next[];  //小写回编译错误
 void kmp_pre(char x[], int m)
 {
     int i,k;
     Next[] = -;
     k = -;
     i = ;
     while(i < m)
     {
         while(- != k && x[i] != x[k])
             k = Next[k] ;
         if(x[i + ] == x[k + ])
             Next[++i] = Next[++k];
         else
             Next[++i] = ++k;
     }
 }
 int kmp_Count(char x[], int m, char y[],int n)
 {
     int i,j;
     int ans = ;
     kmp_pre(x,m);
     i = j = ;
     while(i < n)
     {
         while(- != j && y[i] != x[j])
             j = Next[j];
         i++;
         j++;
         if(j >= m)
         {
             ans++;
             j = Next[j];
         }
     }
     return ans;
 }
 int main()
 {
     int n;
     char t[ + ],p[ + ];
     scanf("%d", &n);
     while(n--)
     {
         scanf("%s%s", t,p);
         int m = strlen(t);
         int n = strlen(p);
         printf("%d\n",kmp_Count(t,m,p,n));
     }
     return ;
 }

KMP讲解

http://www.cnblogs.com/tangzhengyue/p/4315393.html