hdu 2087 剪花布条

点击打开链接hdu2087

代码：

#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;

#define MAXN 1010

int ans;
char text[MAXN];
char pattern[MAXN];
int next[MAXN];

/*求next数组*/
void getNext(){
   int m = strlen(pattern);
   next[0] = next[1] = 0;
   for(int i = 1 ; i < m ; i++){
      int j = next[i];
      while(j && pattern[j] != pattern[i])
         j = next[j];
      next[i+1] = pattern[i] == pattern[j] ? j+1 : 0;
   }
}

/*匹配*/
void find(){
   ans = 0;
   int m = strlen(pattern);
   int n = strlen(text);
   int j = 0;/*模式串的下标*/
   for(int i = 0 ; i < n ; i++){
      while(j && pattern[j] != text[i])
         j = next[j];
      if(pattern[j] == text[i])
         j++;
      if(j == m){
         ans++;
         j = 0;/*这个地方注意防止出现输入aaaaaa aa 输出5的情况*/
      }
   }
   printf("%d\n" , ans);
}


int main(){
   while(1){
      scanf("%s" , text);
      if(!strcmp(text , "#"))
         break;
      scanf("%s" , pattern);
      getNext();
      find();
   }
   return 0;
}