简单易懂（C语言代码）

#include<stdio.h>

int isP(int x)

{

    int temp = 0, p = x;

    while (x)

    {

        temp = temp * 10 + x % 10;

        x /= 10;

    }

    if (p == temp)

        return 1;

    return 0;

}

int sum(int x)

{

    int sum = 0;

    while (x)

    {

    sum += x % 10;

    x /= 10;

    }

    return sum;

}

int main()

{

    int n,count = 0;

    scanf("%d", &n);

    for (int i = 10000; i <= 999999; i++)

    {

        if (isP(i) && sum(i) == n)

        {

            count++;

            printf("%d\n", i);

        }

    }

    if (count == 0)

    printf("-1\n");

}