求更简单的方法（下面那个是我写的）

Description
由键盘输入5个字符，将其中的大写字符变成小写（其它类型的字符不变），最后，按输入顺序输出这5个字符。

输入样例
ApPLe

输出样例
apple

#include <stdio.h>
int main()
{
char ch1,ch2,ch3,ch4,ch5;
scanf("%c%c%c%c%c",&ch1,&ch2,&ch3,&ch4,&ch5);
ch1=(ch1>='A'&&ch1<='Z')?(ch1+'a'-'A'):ch1;
ch2=(ch2>='A'&&ch2<='Z')?(ch2+'a'-'A'):ch2;
ch3=(ch3>='A'&&ch3<='Z')?(ch3+'a'-'A'):ch3;
ch4=(ch4>='A'&&ch4<='Z')?(ch4+'a'-'A'):ch4;
ch5=(ch5>='A'&&ch5<='Z')?(ch5+'a'-'A'):ch5;
printf("%c%c%c%c%c",ch1,ch2,ch3,ch4,ch5);
return 0;
}

#include <stdio.h>
int main()
{
char ch[5];
int i;
for(i=0;i<5;i++)
{
      scanf("%c",&ch[i]);
      ch[i]=(ch[i]>='A'&&ch[i]<='Z')?(ch[i]+'a'-'A'):ch[i];
}
for(i=0;i<5;i++)
      printf("%c",ch[i]);
return 0;
}

供参考：

#include<stdio.h>
int main()
{
    char ch;
    while ((ch = getchar()) != EOF)//ctrl+z结束输入
    {
        if (ch >= 'A' && ch <= 'Z')
            printf("%c", ch + 32);
        else if (ch >= 'a' && ch <= 'z')
            printf("%c", ch - 32);
        else
            printf("%c", ch);
    }
    return 0;
}

#include <stdio.h>
int main() {
    char ch[5];
    for (int i=0;i<5;i++){
        ch[i]=getchar();
        ch[i]=(ch[i]>='A'&&ch[i]<='Z')?(ch[i]+'a'-'A'):ch[i];
    } 
    for(int i = 0;i<5;i++){
        printf("%c",ch[i]);
    }
}