KMP算法

KMP算法：

next函数如图所示：

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

int next[100];

int getnext(char t[]){
    int i = 0,j = -1;
    next[0] = -1;
    while(i < strlen(t)-1){
         if(j == -1 || t[i] == t[j]){
              i++;
              j++;
              next[i] = j;
         }else
         j = next[j];
    }
    for(int i = 0;i < strlen(t);i++){
         printf("%d ",next[i]);
    }
    printf("\n");
}

int main(){
    char s[100],t[100];
    /* s是原始串，t是被匹配串 */
    int i,j;
    while(scanf("%s%s",s,t) != EOF){
         memset(next,0,sizeof(next));
         getnext(t);
         i = 0,j = 0;
         int lens = strlen(s),lent = strlen(t);
         while(i < lens){
               if((j == -1) || (s[i] == t[j])){
                   i++;
                   j++;
                   if(j == lent){
                       printf("%d ",i - lent);
                       j = 0;
                   }
               }
               else{
                   j = next[j];
               }
         }
         printf("\n");
    }
    system("pause");
}