题解 | #字母大小写转换#

#include <stdio.h>

int main() 
{
    char ch = 0;
    while (~scanf("%c", &ch))
    {
        getchar();
        if (ch >= 'A' && ch <= 'Z')  ch += 32;
        else if (ch >= 'a' && ch <= 'z')  ch -= 32;
        printf("%c\n", ch);
    }
    
    return 0;
}