KMP算法：主串、模式串，next【lenT】数组下标从0开始_kmp算法 next数组j从0开始

#include <stdio.h>
 
#include <string.h>
#define N 100
using namespace std;
void Next(int next[],int lenT,char* T)
{
	int i=0,j=-1;
	
	next[0]=-1;
	while (i<lenT)
	{
		if(j==-1 || T[i]==T[j])
		{
			i++;j++;
			next[i]=j;
		}
		else
		j=next[j];
	}
	
}
int KMP(char*S,char*T,int lenS,int lenT)
{
	int next[lenT];
	Next(next,lenT,T);
	int i=0,j=0;
	while (i<lenS&&j<lenT)
	{
		if(j==-1 || S[i]==T[j])
		{
			i++;j++;
		}
		else
		{
			j=next[j];
		}
	}
	if(j==lenT)
	{
		return i-lenT+1;
	}
	else return 0;
}
int main()
{
	char S[N],T[N];
	int lenS,lenT;
	for(int i =1;i<=3;i++)
	{
		S[N]={0};
		T[N]={0};
		scanf("%s",S);
	
		lenS=strlen(S);	//printf("%d\n",lenS );
		scanf("%s",T);
		lenT=strlen(T);	//printf("%d", lenT);
		
		printf("%d\n",KMP(S,T,lenS,lenT));	
	}
	
    return 0;
}