程序代码：

#include<stdio.h>
#include<string.h>
void sort(char a[], int n)
{
    int i, j;
    for (i = 0; i < n - 1; i++)
    {
        for (j = i + 1; j< n; j++)
        {
            if (a[i] < a[j])
            {
                char temp;
                if ((a[j] >= 'a') && (a[i] <= 'a'))
                {
                    if ((a[i] - 'A') < (a[j] - 'a'))
                    {
                        continue;
                    }
                }
                temp = a[i];
                a[i] = a[j];
                a[j] = temp;
            }
            else
            {
                char temp;
                if ((a[i] >= 'a') && (a[j] <= 'a'))
                {
                    if ((a[i] - 'a') <= (a[j] - 'A'))
                    {
                        temp = a[i];
                        a[i] = a[j];
                        a[j] = temp;
                    }
                }
                
            }
        }
    }
}

int main()
{
    char a[] = "ageAGE";

    sort(a, strlen(a));
    
    printf("%s\n",a);
    return 0;


}