01
要求
从键盘输入一串数字，将其中的最大数、第二大数打印输出

02
程序

#include <stdio.h>
    
int main()
{
    int a[99];
    int i=0;
    int len=0;
    char ch;
    
    printf ("Please input numbers:");
    
    while(ch=getchar()!='\n')
    {
        scanf ("%d",&a[i]);
        i++;
        len++;
    }
    
    int max1=a[0];
    for (i=1;i<len;i++)
    {
        if (max1<a[i])
        {
            max1=a[i];
        }
    }

    printf ("Max1 = %d\n",max1);
    
    int max2=a[0];
    
    for (i=0;i<len;i++)
    {
        if (max1==max2)
        {
            max2=a[i+1];
        }
        if (max2<a[i] && a[i]!=max1)
        {
            max2=a[i];
        }    
    }
    printf ("Max2 = %d\n",max2);
    
    return 0;
}

03
结果

Please input numbers:33 44 55 66 66 6 66 55
Max1 = 66
Max2 = 55