题解 | #大小写转换#

#include <stdio.h>
int main()
{
    char ch = ' ';
    while ((ch = getchar()) != EOF) {
        getchar();
        if(ch >= 'A' && ch <= 'Z')
        {
            ch += 32;
            putchar(ch);
            printf("\n");
        } else if(ch >= 'a' && ch <= 'z')
        {
            ch-=32;
            putchar(ch);
        }
    }

    return 0;
}