（Problem 4）Largest palindrome product

A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91  99.

Find the largest palindrome made from the product of two 3-digit numbers.

#include<stdio.h>

#include<math.h>

#include<string.h>

#include<ctype.h>

#include<stdlib.h>

#include<stdbool.h>





bool palindromic(int n)  //判断一个整数是否为回文数

{

    char s[10];

    sprintf(s,"%d",n);  //将整数n保存在字符数组s中

    int i,len;

    len=strlen(s);

    for(i=0; i<len/2; i++)

    {

        if(s[i]!=s[len-i-1])

            return false;

    }

    return true;

}



bool have_the_factor(int n)   //判断是否含有两个3位数的因数

{

    int s=999;

    int r,b;

    while(s>100)

    {

        if((n%s)==0 && ((n/s)>100  && (n/s)<1000))

            return true;

        s--;

    }

    return false;

}



int main()

{

    int i=1000000;

    while(i>0)

    {

        if(palindromic(i) && have_the_factor(i))

        {

            printf("%d\n",i);

            break;

        }

        i--;

    }

    return 0;

}

Answer:

906609