给出一个不多于5位的整数，要求 1、求出它是几位数 2、分别输出每一位数字 3、按逆序输出各位数字，例如原数为321,应输出123

#include <stdio.h>
#include <stdlib.h>
int main()
{
    int x, a, b, c, d, e;
    //输入一个整数
    printf("Please enter number: ");
    scanf("%d", &x);
    //以下是判断整数是否多于5位，多于判断出错，重新输入
    while (x < 0 || x > 99999){
        printf("Error! Retry!\nPlease enter number: ");
        scanf("%d", &x);
    }
    //以下判断出该数是几位数
    a = x / 10000;
    b = x / 1000;
    c = x / 100;
    d = x / 10;
    e = x - d * 10;
    if (a >= 1 && a <= 9){
        printf("%d is 5 bits!\n", x);
        printf("%d %d %d %d %d\n", a, b-a*10, c-b*10, d-c*10, e);
        printf("%d %d %d %d %d\n", e, d-c*10, c-b*10, b-a*10, a);
    }
    else if (b >= 1 && b <= 9){
        printf("%d is 4 bits!\n", x);
        printf("%d %d %d %d\n", b, c-b*10, d-c*10, e);
        printf("%d %d %d %d\n", e, d-c*10, c-b*10, b);
    }
    else if (c >= 1 && c <= 9){
        printf("%d is 3 bits!\n", x);
        printf("%d %d %d\n", c, d-c*10, e);
        printf("%d %d %d\n", e, d-c*10, c);
    }
    else if (d >= 1 && d <= 9){
        printf("%d is 2 bits!\n", x);
        printf("%d %d\n", d, e);
        printf("%d %d\n", e, d);
    }
    else{
        printf("%d is 1 bits!\n", x);
        printf("%d\n", x);
    }
    system("pause");
    return 0;
}

#include <stdio.h>

int main( void )
{
    int n;
    scanf( "%d", &n );

    unsigned count = 0;
    char s[40] = { '-', '0', 0 };
    char* p = s;
    for( unsigned m=n<0?-n:+n; m; m/=10 )
    {
        ++count;
        if( p!=s || m%10!=0 )
            *++p = m%10+'0';
    }

    printf( "%u, %s\n", count==0?1:count, s+(n>=0) );
}