输入：
1234
输出
1 2 3 4

输入：
1000
输出
1 0 0 0

输入：
0
输出
0

代码

//c语言非负整数分解
//12345 / 10000 = 1;
//12345 % 10000 = 2345;
// 10000/10 = 1000; mask2
//每次做以上3件事，直到mask<10; 
//2345 /1000 = 2;
//2345 % 1000 = 345;
//1000 / 10 =100;   mask3
//345 /100 = 3;
//345 %100 = 45;
//100/10= 10;   mask4
//45/10=4;
//45%10=5;
//10/10=1;  mask5
//5/1=5;
//5%1=0;
//1/10=0    mask6

#include<stdio.h>

int main()
{
    int x;
    int t = 0;
    int mask = 1;
    int d;
    printf("input x: ");
    scanf("%d",&x);
    t = x;
    //先求mask是否大于1
    printf("mask的变化:\n"); 
    while(t>9)
    {
        mask = mask*10;
        t = t/10;       
        printf("%d\n",mask);
    }
    printf("\n");
    //按照之前的算法求每位数
    do
    {
        d = x / mask ;
        printf("%d",d); 
        if(mask>9)
        {
            printf("*");//最后一个空格不输出 
        }
        x %= mask;
        mask = mask/10;         
    }while(mask>0);
    return 0;
}

输出

输出1.PNG
输出2.PNG
输出3.PNG

由于空格在cmd界面不容易看出，故以*代替

本程序在Dev-c++编译运行成功