[cpp]
#include <stdio.h>
#include <string.h>
#define MAXSIZE 100
int next[MAXSIZE];
int S_lenth,D_lenth;
char source[MAXSIZE],detination[100];
void get_next()
{
int i=1,j=0;
next[1]=0;
while(i<=D_lenth)
{
if(j==0||(detination[i-1]==detination[j-1]))
{
++i;
++j;
next[i]=j;
}
else
{
j=next[j];
}
}
}
int KMP()
{
int i=0,j=1;
while(i<=S_lenth&&j<=D_lenth)
{
if(j==0||(source[i]==detination[j-1]))
{
++i;
++j;
}
else
{
j = next[j];
}
}
if(j>D_lenth)
{
return i-D_lenth;
}
else
return 0;
}
int main()
{
int i=0;
printf("输入源串！！！\n");
scanf("%s",&source);
printf("输入模式串！！！\n");
scanf("%s",&detination);
S_lenth = strlen(source);
D_lenth = strlen(detination);
get_next();
printf("next数组元素为：\n");
for(i=1;i<=D_lenth;i++)
{
printf("%d ",next[i]);
}
printf("\n模式串开始于源串%d位置处",KMP());
return 0;
}