最长回文子串

#include <stdio.h>
#include <string.h>
#define MAX 10000
int min(int a,int b)
{
return a>b?b:a;
}
void rebuild(char *s,char *src)
{
int i;
s[0]='$',s[1]='#';
for(i=0; i<strlen(src); ++i)
{
s[2*i+2]=src[i];
s[2*i+3]='#';
}
s[2*i+2]='0';
}
int longestSubStrNum(char *s)
{
int p[2*MAX+2]= {1,1},id=1,mx=2,i,maxlen=0;
for (i = 2; s[i] != '\0'; i++)
{
p[i] = mx > i ? min(p[2*id-i], mx-i) : 1;
while (s[i + p[i]] == s[i - p[i]]) p[i]++;
if (i + p[i] > mx)
{
mx = i + p[i];
id = i;
}
if(maxlen<p[i]-1)maxlen=p[i]-1;
}
return maxlen;
}
int main()
{

char src[MAX],s[2*MAX+2];
scanf("%s",&src);
rebuild(s,src);
printf("最长回文串的长度为：%d\n",longestSubStrNum(s));
return 0;
}