1185.一周中的第几天.cpp

/*
 * @lc app=leetcode.cn id=1185 lang=cpp
 *
 * [1185] 一周中的第几天
 */
#include "a_header.h"
// @lc code=start
class Solution
{
public:
    string dayOfTheWeek(int day, int month, int year)
    {
        vector<string> week = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"};
        vector<int> monthDays = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30};
        /* 输入年份之前的年份的天数贡献 */
        int days = 365 * (year - 1971) + (year - 1969) / 4;
        /* 输入年份中，输入月份之前的月份的天数贡献 */
        for (int i = 0; i < month - 1; ++i)
        {
            days += monthDays[i];
        }
        if ((year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) && month >= 3)
        {
            days += 1;
        }
        /* 输入月份中的天数贡献 */
        days += day;
        return week[(days + 3) % 7];
    }
};
// @lc code=end