代码中定义3个变量：
unsigned short year;
unsigned char  month;
unsigned char day;
写代码scanf来让用户输入年、月、日的值。

#include <stdio.h>
int main()
{

	unsigned short year;
	unsigned char  month;
	unsigned char day;
	int y, m, d;
	scanf_s("%d%d%d", &y, &m, &d); //由于scanf只能接收int型的变量
	//类型转化
	year = (unsigned short)y; 
	month = (unsigned char)m;
	day = (unsigned char)d;
	printf("%d-%d-%d\n", year, month, day);
	return 0;
}