牛客网 2018校招真题 美丽联合 计算一年中的第几天

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Description

牛客网 2018校招真题 计算一年中的第几天

Solving Ideas

闰年判断有两个条件，只要满足其一即可：

• 能被4整除但不能被100整除
• 能被400整除

Time complexity : $O(1)$
Space complexity : $O(1)$

Solution

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * @author wylu
 */
public class Main {
    static int[] DAYS_OF_MONTH = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] strs = br.readLine().split(" ");

        int year = Integer.parseInt(strs[0]);
        int month = Integer.parseInt(strs[1]);
        int day = Integer.parseInt(strs[2]);

        boolean flag = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
        int res = 0;
        for (int i = 1; i < month; i++) res += DAYS_OF_MONTH[i];
        if (flag && month > 2) res++;
        System.out.println(res + day);
    }
}