1185. 一周中的第几天

1185. 一周中的第几天层

• 难度: easy
• 原始链接: https://leetcode.cn/problems/day-of-the-week
• 标签: 模拟

解法一: 按年份一次计算

go

func dayOfTheWeek(day int, month int, year int) string {
    daySum := 0
    for i := 1970; i < year; i++ {
        if isLeep(i) {
            daySum += 366
        } else {
            daySum += 365
        }
    }
    months := []int{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
    for i := 1; i < month; i++ {
        daySum += months[i - 1]
    }
    if month > 2 && isLeep(year) {
        daySum++
    } 
    daySum += day
    days := []string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}
    return days[(daySum + 3) % 7]
}

func isLeep(year int) bool {
    return (year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))
}

解法二: 日期工具类

java

class Solution {
    public String dayOfTheWeek(int day, int month, int year) {
        String[] weeks = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"};
        LocalDate date = LocalDate.of(year, month, day);
        return weeks[date.getDayOfWeek().getValue() - 1];
    }
}