kmp 算法

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int next[1000];
int nextval[1000];

void get_next(char *str)
{
    int i = 1 , j = 0, len;
    str[0] = strlen( (str + 1));
    next[1] = 0;
    while ( i < str[0] ) {
        if ( j == 0 ||  str[i] == str[j] )
            i++, j++, next[i] =  j;
        else
            j = next[j];
    }
}

void get_nextval ( char *str)
{
  int i = 1, j = 0;
  nextval[1] = 0;
  str[0] = strlen (str + 1);
  while ( i < str[0] ) {
   if (str[i] == str[j] || j == 0) {
               i++, j++;
   if (str[i] != str[j] ) 
           nextval[i] = j;
   else
           nextval[i] = nextval[j];
   }
   else
       j = nextval[j];
  }  
}     
  

int index_kmp ( char *S, char *T)
{
    int i = 1, j = 1;
    S[0] = strlen(S + 1);
    T[0] = strlen(T + 1);
    while ( i <= S[0]  && j <=  T[0]) {
        if ( j == 0 ||  T[j] == S[i] ) {
           i++, j++;
        }
        else
            j = nextval[j];
    }
  
   if ( j > T[0])
        return  i - T[0];
   return  0;
}



int main( )
{
    char ch[30];
    char sh[100];

    while (scanf("%s%s",sh+1, ch+1) != EOF ) {
            memset(next, 0, sizeof(next));
             get_next(ch);
             get_nextval(ch);
         printf("%d\n",index_kmp(sh,ch));
    }
    return 0;
}