题解 | #字母大小写转换#

#include <stdio.h> #include <ctype.h>

int main(void) {

char ch;

while (scanf("%c", &ch) != EOF)
{
    if (islower(ch))
        putchar(ch - 32);
    else if (isupper(ch))
        putchar(ch + 32);
    else if (ch == '\n')
        putchar('\n');
}

return 0;

}