[c] 万年历

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define str "   SUN   MON  TUE   WED   THU   FRI   SAT   "

void menu();         //操作菜单
int leap(int year);        //判断某年是不是闰年
int days_month(int year, int month);        //返回某月的天数
int someday(int year, int month, int day);    //计算某天是星期几
void search_month(int year, int month);        //输出某月的日历
void search_someday(int year, int month, int day);    //查询某日是星期几

int main()
{
	int i, year, month, day;
	int k1, k2, k3, k4;    //用于判断输入的数据和操作是否正确，1代表正确，0代表错误
	int a = 1;
	menu();
	do
	{
		printf("请输入你要进行的操作(1-4):");
		scanf_s("%d", &i);
		getchar();
		switch (i)
		{
		case 1:
			printf("请输入你要查询的年份："); scanf_s("%d", &year);
			for (a; a <= 12; a++)
			{
				printf("\n\n---------*******   %d  *******------------\n", a);
				search_month(year, a);
			}
			printf("---------*********************------------\n\n\n");
			break;


		case 2:
			printf("请输入您所要查询的相关信息.\n");
			printf("年份："); scanf_s("%d", &year);
			printf("月份："); scanf_s("%d", &month);
			k1 = 1;
			while (k1)
			{
				if (month > 12 || month < 1)
				{
					printf("你输入的月份有误，请重新输入!\n");
					printf("月份:");
					scanf_s("%d", &month);
					if (month < 1 || month>12)    k1 = 1;
				}
				else k1 = 0;
			}
			search_month(year, month);
			printf("---------*********************------------\n\n\n");
			break;


		case 3:
			printf("请输入你要查询的日期\n");
			printf("年份："); scanf_s("%d", &year);
			printf("月份："); scanf_s("%d", &month);
			k2 = 1;
			while (k2)
			{
				if (month > 12 || month < 1)
				{
					printf("你输入的月份有误，请重新输入!\n");
					printf("月份:");
					scanf_s("%d", &month);
					if (month < 1 || month>12)    k2 = 1;
				}
				else k2 = 0;
			}
			//    printf("%d年%d月有%d天\n",year,month,days_month(year,month));     调试观察输入的日期是否有误，可忽略
			printf("日期："); scanf_s("%d", &day);
			k3 = 1;
			while (k3)
			{
				if (day > days_month(year, month) || day < 1)
				{
					printf("你输入的日期有误，请重新输入!\n");
					printf("日期:");
					scanf_s("%d", &day);
					if (day > days_month(year, month) || day < 1)    k3 = 1;
				}
				else k3 = 0;
			}
			search_someday(year, month, day);
			printf("---------*********************------------\n\n\n"); break;


		case 4:exit(0);
			printf("---------*********************------------\n\n\n"); break;


		default:
			k4 = 1;
			while (k4)
			{
				printf("你输入的数据有误，请重新输入你要进行的操作(1-4):");
				scanf_s("%d", &i);
				if (i < 1 || i>4)    k4 = 1;
				else k4 = 0;
			}
			break;
		}
	} while (i > 0 && i < 5);
	return 0;
}

void menu()
{
	int i = 1;
	printf("\n\n\t\t----------------------------------------\n");
	printf("\t\t|--------------------------------------|\n");
	printf("\t\t|           %d.  输出某年的日历         |\n", i);
	printf("\t\t|           %d.  输出某月的日历         |\n", i + 1);
	printf("\t\t|           %d.  查询某日是星期几       |\n", i + 2);
	printf("\t\t|           %d.  退出系统               |\n", i + 3);
	printf("\t\t|--------------------------------------|\n");
	printf("\t\t----------------------------------------\n\n");

}

int leap(int year)
{
	if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) return 1;
	else return 0;
}

int days_month(int year, int month)
{
	int days_month;
	switch (month)
	{
	case  1:
	case  3:
	case  5:
	case  7:
	case  8:
	case  10:
	case  12: days_month = 31; break;

	case  4:
	case  6:
	case  9:
	case  11:days_month = 30; break;

	case  2:
		if (leap(year) == 1)
		{
			days_month = 29; break;
		}
		else days_month = 28; break;
	}
	return days_month;
}

int someday(int year, int month, int day)
{
	//该函数运用了特殊的计算公式，详细可参见 http://blog.163.com/hexin_mars_blog/blog/static/248215040201571351115699/
	int someday, m, n, i;  //someday表示查询的日子是星期几
	m = year - year / 1000 * 1000;
	n = m - m / 100 * 100 - 1;            //用于获得年份的后两位数
	int days = 0;
	for (i = 1; i < month; i++) days = days + days_month(year, i);
	days = days + day;
	someday = (n + n / 4 - n / 100 + n / 400 + days) % 7;
	return someday;
}

void search_someday(int year, int month, int day)
{
	char weekname[20];
	switch (someday(year, month, day))
	{
	case 0:strcpy_s(weekname, "星期天"); break;
	case 1:strcpy_s(weekname, "星期一"); break;
	case 2:strcpy_s(weekname, "星期二"); break;
	case 3:strcpy_s(weekname, "星期三"); break;
	case 4:strcpy_s(weekname, "星期四"); break;
	case 5:strcpy_s(weekname, "星期五"); break;
	case 6:strcpy_s(weekname, "星期六"); break;
	}
	printf("你所要查询的日期是%s\n", weekname);
}

void search_month(int year, int month)
{
	int i = 0, j, k = 0, m;     //j用于记录某月的第一天是星期几   m用于记录某月的天数  k用于换行提示
	char x[10] = "      ";
	m = days_month(year, month);
	j = someday(year, month, 1);

	//输出某月的日历
	printf("------------------------------------------\n");
	printf("%s\n", str);
	for (; i < j; i++)
	{
		printf("%s", x); k++;
	}
	for (i = 1; i <= m; i++)
	{
		k++;
		if (k % 7 == 0)
		{
			if (i < 10)
			{
				printf("    %d ", i);
				printf("\n");
			}
			else if (i >= 10)
			{
				printf("   %d ", i);
				printf("\n");
			}
		}
		else
		{
			if (i < 10)
			{
				printf("    %d ", i);
			}
			else if (i >= 10)
			{
				printf("   %d ", i);
			}
		}
	}
	printf("\n------------------------------------------\n");
}

void exit()
{
	exit(0);
}

 

本文地址：https://blog.csdn.net/xwh012510/article/details/85989654