（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