编程之美3.1 字符串移位包含问题

直接按照书上所说代码实现的，就是把两个串连接起来，利用了KMP算法实现字符串的匹配，直接贴代码：

#include "stdafx.h"
#include <IOSTREAM>

using namespace std;

void ComputePrefix(const char *str, int *pi){
    if(NULL==str || NULL==pi)
        return;
    int len = strlen(str);
    pi[0] = 0;
    int k = 0;
    for (int i=2; i<=len; i++)
    {
        while (k>0 && str[k]!=str[i-1])
            k = pi[k-1];
        if(str[k] == str[i-1])
            k++;
        pi[i-1] = k;
    }
}

bool KMP(const char *str1, const char *str2){
    bool isMatch = false;
    int len1 = strlen(str1);
    int len2 = strlen(str2);
    
    int *pi = new int[len2];
    if(NULL!=pi)
        ComputePrefix(str2,pi);
    else
        return false;

    int k=0;
    for (int i=1; i<=len1; i++)
    {
        while (k>0 && str2[k]!=str1[i-1])
            k = pi[k-1];
        if(str2[k]==str1[i-1])
            k++;
        if(k==len2){
            isMatch = true;
            break;
        }
    }

    delete[] pi;
    return isMatch;
}

bool isInclude(char* str1, char *str2){
    if(NULL==str1 || NULL == str2)
        return false;

    int len1 = strlen(str1);
    int len2 = strlen(str2);
    if(len2!=len1)
        return false;
    char *strTemp = new char[len1+len2+1];
    if(NULL == strTemp)
        return false;
    strcpy(strTemp, str1);
    strcat(strTemp, str1);
    cout << strTemp << endl;
    
    bool isIN = KMP(strTemp,str2);
    delete[] strTemp;
    return isIN;
}

int main(int argc, char* argv[])
{
    cout << isInclude("ABCD","DCAB") << endl;
    return 0;
}