判断闰年，用三种不同的方法交换两个数的值

3. 判断1000年---2000年之间的闰年
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
int year = 0;
int count = 0;
for (year = 1000; year <= 2000; year++)
{
if (year % 4 == 0)
{
if (year % 100 != 0)
{
printf("%d ", year);
count++;
}
}
if (year % 400 == 0)
{
printf("%d ", year);
count++;
}
}
printf("\ncount=%d", count);
system("pause");
return 0;
}
4. 给定两个整形变量的值，将两个值的内容进行交换。（或不允许创建临时变量）{异或的效率低，可读性差，还不如加减}
int main()
{
int a = 0;
int b = 0;
scanf("%d%d", &a, &b);
a = a^b;
b = a^b;
a = a^b;
//a = a + b;
//b = a - b;
//b = a - b;
/*int tmp = 0;
tmp = a;
a = b;
b = tmp;*/
printf("%d %d", a, b);
system("pause");
return 0;
}