/*写入一个小写字母，以小写输出，大写变小写；
#include
int main(){
char c,result;
printf("input a char: ");
scanf("%c",&c);
printf("你输入的是%c\n",c);
result=('a'<=c&&c<='z')?(c-'a'+'A'):c;
printf("转换后%c\n",result);
return 0;
}
//简单的四则运算。由符号（+ - * /）控制。
#include
int main(){
int a, b;
char c;
printf("请输入两个数和一个符号：a(*,/,-,+)b ");
scanf("%d %c %d",&a, &c, &b);
printf("a=%d,b=%d\n",a,b);
switch(c){
case '*':printf("%d\n",a * b);break;
case '/':printf("%d\n",a / b);break;
case '-':printf("%d\n",a - b);break;
case '+':printf("%d\n",a + b);break;
default:printf("ERROR! \n");
}
return 0;
}
/*数字拆分*/ 倒序输出 123 --> 321
#include
int main(){
//1步
int num,result;
printf("请输入num： ");
scanf("%d",&num);
//2步
int a = num%10;
int b = num/10%10;
int c = num/100%10;
if(c!=0){
result = c+10*b+100*a;
}
else if(c==0 && b!=0){
result=c*0+b+10*a;
}
else{
result = a;
}
printf("%d---%d\n",num,result);
return 0;
}