c - C中的回文问题

Question

我已经用 C 语言编写了一些代码来尝试判断一个数字是否为回文。规则是两个 3 位数字必须相乘，并且您必须找到最高的回文数。答案应该是 906609，但我的代码只能得到 580085。

代码:

#include <stdio.h>
#include <stdlib.h>

/* Intialise */
void CalcPalin();
int CheckPalin(int number);

/* Functions */
void CalcPalin()
{
    int result = 0;
    int palin = 0;
    int FNumber = 0;
    int FNumber2 = 0;

    int number = 99;
    int number2 = 100;

    while(number2 < 1000)
    {
        number += 1;

        /*times together - calc result*/
        result = number * number2;

        if(CheckPalin(result) == 1)
        {
            palin = result;
            FNumber = number;
            FNumber2 = number2;
        }

        if(number == 999)
        {
            number = 99;
            number2 += 1;
        }
    }
    printf(" Result = %d, by Multiplying [%d] and [%d]", palin, FNumber, FNumber2 );
}

int CheckPalin(int number)
{
    int checknum, checknum2 = 0;

    checknum = number;
    while(checknum)
    {
        checknum2 = checknum2 * 10 + checknum % 10;
        checknum /= 10;
    }

    if( number == checknum2)
        return 1;
    else
        return 0;
}

int main( void)
{
    CalcPalin();
    return EXIT_SUCCESS;
}

我很确定这是一个愚蠢的答案，我正在寻找一些简单的东西，但我似乎找不到它。任何帮助都会很棒

Answer 1

您还没有测试当前结果是否高于旧结果。添加此检查。

// test new result is higher than old palin before setting this as palin
if(CheckPalin(result) == 1 && palin < result)