用C语言编写：输入四个整数，按由小到大输出

Answer 1

可以用数组存储这4个数，然后用冒泡法进行排序，具体代码如下：
#include <stdio.h>
void main()
{
int i,j,temp;
int a[4];
printf("请输入四个数:\n");
for(i = 0;i < 4;i++)
scanf("%d",&a[i]);
for(i = 0;i<3;i++)
{
for(j = i+1;j<4;j++)
{
if(a[i] > a[j])
{
temp = a[j];
a[j] = a[i];
a[i] = temp;
}
}
}
printf("\n排序后的数组是:\n");
for(i = 0; i <4;i++)
printf("%d ",a[i]);
printf("\n");
}

Answer 2

冒泡法就好了吧～
代码：

#include <stdio.h>
int main()
{
int i, n=4, j, m;
int a[]={0,0,0,0};
printf("\nInput 4 integers are as below:\n\n");
scanf("%d %d %d %d",a,a+1,a+2,a+3);
printf("==============Your Input==============\n");
for (i=0; i<n; i++)
{
printf("%10d",a[i]);
if ((i+1)%10==0)
printf("\n");
}
for (i=1; i<n; i++)
{
for (j=0; j<n-i; j++)
{
if (a[j]>a[j+1])
{
m=a[j];
a[j]=a[j+1];
a[j+1]=m;
}
}
}
printf("\nThe sorted integers:\n\n");
for (i=0; i<n; i++)
{
printf("%10d",a[i]);
if ((i+1)%10==0)
printf("\n");
}
}

结果示例，输入用空格隔开：

Input 4 integers are as below:

10 8580 5 21654
==============Your Input==============
10 8580 5 21654
The sorted integers:

5 10 8580 21654

Answer 3

你想想如果是你来做这道题的话怎么做，然后把它写成C语言就行了