C语言_日期_周计算（二）

àì夳堔傛蜴生んèń 2022-11-05 11:57 8阅读 0赞

# 日期计算 #

## 计算指定日期是周几 ##

void CaculateWeekDay(int y, int m, int d)
    { 
    	if (m == 1 || m == 2) { 
    		m += 12;
    		y--;
    	}
    	int iWeek = (d + 2 * m + 3 * (m + 1) / 5 + y + y / 4 - y / 100 + y / 400) % 7;
    	switch (iWeek)
    	{ 
    	case 0: cout << "星期一" << endl; break;
    	case 1: cout << "星期二" << endl; break;
    	case 2: cout << "星期三" << endl; break;
    	case 3: cout << "星期四" << endl; break;
    	case 4: cout << "星期五" << endl; break;
    	case 5: cout << "星期六" << endl; break;
    	case 6: cout << "星期日" << endl; break;
    	}
    }

【参考】

1.  [C++输入日期判断是星期几][C]

## 获取一年中周一（日期）的数组 ##

// int array[53][4] = {index, year, month, day}
    void GetMondayArray(int y, int(*arr)[4])
    { 
    	int m = 1, 
    		d = 1, 
    		iStart = 1;
    	int MonthMax[13]{  31, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    
    	if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0)	//如果是闰年
    		MonthMax[2] = 29;
    
    	if (m == 1 || m == 2)
    	{ 
    		m += 12;
    		y--;
    	}
    	int iWeek = (d + 2 * m + 3 * (m + 1) / 5 + y + y / 4 - y / 100 + y / 400) % 7;
    
    	y += 1;
    	for (size_t i = 0; i < 53; i++)
    		arr[i][0] = i + 1;
    	if (iWeek)
    	{ 
    		arr[0][1] = y - 1;
    		arr[0][2] = 12;
    		arr[0][3] = 31 - iWeek + 1;
    		m = 0;
    	}
    	else
    	{ 
    		arr[0][1] = y;
    		arr[0][2] = 1;
    		arr[0][3] = 1;
    		m = 1;
    	}
    
    	iStart = arr[0][3];
    	for (int i = 1; i < 53; i++)
    	{ 
    		for (int j = 0; j < 5; j++)
    		{ 
    			iStart += 7;
    			if (iStart > MonthMax[m])
    			{ 
    				iStart -= MonthMax[m];
    				m++;
    				m = m > 12 ? 1 : m;
    				arr[i][2] = m;
    				arr[i][3] = iStart;
    				break;
    			}
    			else
    			{ 
    				arr[i][1] = y;
    				arr[i][2] = m;
    				arr[i][3] = iStart;
    				i++;
    			}
    		}
    		arr[i][1] = y;
    	}
    }
    
    int main()
    { 
    	int year, month, day;
    	/*cout << "请输入年 月 日" << endl; cin >> year; cin >> month; cin >> day; CaculateWeekDay(year, month, day);*/
    	int arr[53][4] = {  0 };
    	GetMondayArray(2021, arr);
    	for (size_t i = 0; i < 53; i++)
    	{ 
    		printf("%d, %d, %d, %d\n", arr[i][0], arr[i][1], arr[i][2], arr[i][3]);
    	}
    	system("pause");
    	return 0;
    }

[C]: https://blog.csdn.net/taotaoah/article/details/52681597