面试题35：寻找一个字符串中最长的重复子串

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAXCHAR 5000 //最长处理5000个字符

char c[MAXCHAR];//字符数组c保存用户输入的字符串
char *a[MAXCHAR];//字符串指针数组a保存用户输入的字符串的所有后缀字符串

//求出两个字符串的公共子串长度
int comlen( char *p, char *q )
{
int i = 0;

while( *p && (*p++ == *q++))
{
++i;
}

return i;
}

//字符串排序规则
int pstrcmp( const void *p1, const void *p2 )
{
return strcmp( *(char* const *)p1, *(char* const*)p2 );
}

int main(void)
{
char ch;
int n = 0;
int i;
int temp;
int  maxlen=0;
int maxi=0;

printf("Please input your string:\n");
while ((ch=getchar()) != '\n')
{
//给数组赋初值
a
= &c
;
c[n++] = ch;
}

c
= '\0';
qsort (a, n, sizeof(char*), pstrcmp );//将后缀字符串集合进行排序

for (i=0; i<n-1; ++i)
{
temp = comlen(a[i], a[i+1]);
if( temp > maxlen )
{
maxlen = temp;
maxi = i;
}
}

printf("%s\n", a[maxi]);
system("PAUSE");
return 0;
}