KMP搜索算法

/*============================================================================
 Name        : Exercise.cpp
 Author      : Haier
 Version     : 1.01
 Copyright   : Copyright (c) 2014
 Description : KmpSearch in C, Ansi-style, Compile by Eclipse
 ============================================================================*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

const char *KmpSearch(const char *OriString,const char *SubString)
{
    int *T;
    int i,j;
    const char *Position=NULL;

    if(SubString[0]=='\0')
    {
        return OriString;
    }

    T=(int*)malloc((strlen(SubString)+1)*sizeof(int));
    T[0]=-1;
    /* Construct the lookup table */
    for(i=0; SubString[i]!='\0'; i++)
    {
        T[i+1]=T[i]+1;

        while(T[i+1]>0 && SubString[i]!=SubString[T[i+1]-1])
        {
            T[i+1] = T[T[i+1]-1]+1;
        }

    }
    /* Perform the search */
    for(i=j=0; OriString[i]!='\0';)
    {
        if(j<0 || OriString[i]==SubString[j])
        {
            i++,j++;

            if(SubString[j]=='\0')
            {
                Position=OriString+i-j;
                break;
            }
        }
        else
        {
            j=T[j];
        }
    }

    free(T);
    return Position;
}
int main()
{
    char *MyString="Hello";
    char *Test    ="e";

    printf("%s",KmpSearch(MyString,Test));

    return 0;
}