程序代码：

#include<stdio.h>
#define N 20
int main(void)
{
    unsigned int n,a[N]={0};
    scanf("%d",&n);
    for(int i=0;i<N&&n;i++)
    {
        a[i]=n%4;
        n=n/4;
    }

    for(i=i-1;i>=0;i--)
    {
        printf("%d",a[i]);
    }
    printf("\n");
    return 0;
}

程序代码：

#include<stdio.h>
int main()
{
    unsigned int n;
    int s=0,m;
        printf("please input a number\n:");
    scanf("%u",&n);
    while(n>0)
    {m=n%4;n=n/4;s=s*10+m;}
    printf("the result is：%d\n",s);
}