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// KMP.cpp : 定义控制台应用程序的入口点。
//
#include "stdafx.h"
#include<iostream>
using namespace std;
int BF(char S[], char T[])
{
int i=0, j=0;
int index = 0;
while ((S[i]!=' ')&&(T[j]!=' '))
{
if (S[i]==T[j])
{
i++;
j++;
}
else
{
index++;
i = index;
j = 0;
}
}
if (T[j] == ' ')
return index + 1;
else
{
return 0;
}
}
void getNext(char *p, int *next)
{
int j, k;
next[0] = -1;
j = 0;
k = -1;
while (j<strlen(p) - 1)
{
if (k == -1 || p[j] == p[k]) //匹配的情况下,p[j]==p[k]
{
j++;
k++;
next[j] = k;
}
else //p[j]!=p[k]
k = next[k];
}
}
int KMPMatch(char *s, char *p)
{
int next[100];
int i, j;
i = 0;
j = 0;
getNext(p, next);
while (i<strlen(s))
{
if (j == -1 || s[i] == p[j])
{
i++;
j++;
}
else
{
j = next[j]; //消除了指针i的回溯
}
if (j == strlen(p))
return i - strlen(p);
}
return -1;
}
int _tmain(int argc, _TCHAR* argv[])
{
char *a;
char *b;
char arr0[] = "abcde";
char arr1[] = "cd";
a = arr0;
b = arr1;
cout<<"比较相等的起始值为："<<KMPMatch(a, b);
return 0;
}
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