KMP 算法

/*
  Name: 
  Copyright: 
  Author: 
  Date: 13/07/11 19:14
  Description: 
*/
#include <iostream>  
#include <string>  
using namespace std;  
void InitNext(string szPartern,int* iNext)
{
    iNext[0] = -1;
    int iStrIndex = 0;
    int iNextIndex = -1;
    int iLength = szPartern.size();
    while(iStrIndex < iLength)
    {
        if(iNextIndex == -1 || szPartern[iStrIndex] == szPartern[iNextIndex])
        {
            iNextIndex = iNextIndex  + 1;
            iStrIndex  = iStrIndex  + 1;
            
            iNext[iStrIndex] = iNextIndex;  
        }    
        else
           iNextIndex = iNext[iNextIndex];
    }    
}    
int KmpFind(string szTarget,string szPartern,int* iNext)
{
    int iTargetLength = szTarget.size();
    int iParternLength = szPartern.size();
    int iTargetIndex = 0;
    int iParternIndex =0;
    while(iTargetIndex < iTargetLength && iParternIndex < iParternLength)
    {
        if(iParternIndex == -1 || szTarget[iTargetIndex] == szPartern[iParternIndex])
        {
            if(iParternIndex == iParternLength - 1)
            {
                return iTargetIndex - iParternIndex;
            }    
            iParternIndex = iParternIndex + 1;
            iTargetIndex = iTargetIndex + 1;
        } 
        else
           iParternIndex = iNext[iParternIndex];   
    }   
    return -1; 
}  
void PrintResualt(int iFindIndex)
{
    switch(iFindIndex)
    {
        case -1:
            cout<<"filed to find"<<endl;
            break;
        default:
            cout<<"find index: "<<iFindIndex<<endl;
    }    
}      
int main()
{
    int iNext[100];
    memset(iNext,0,sizeof(iNext));
    string szTarget;
    string szPartern ;
    cout<<"Target string input"<<endl;
    cout<<"Partern string input"<<endl;
    while(cin>> szTarget && cin>>szPartern)
    {
        InitNext(szPartern,iNext);
        int iFindIndex = KmpFind(szTarget,szPartern,iNext);
        PrintResualt(iFindIndex);
    }    
    getchar();
}