题解 | switch case的使用#计算日期到天数转换#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别c
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            String str = in.nextLine();
            String[] sArr = str.split(" ");
            int y = Integer.parseInt(sArr[0]);
            int m = Integer.parseInt(sArr[1]);
            int d = Integer.parseInt(sArr[2]);

            int dNum = 0;

            if (y % 400 == 0 || (y % 4 == 0 && y % 100 != 0)) {
                while (m > 1) {
                    switch (m - 1) {
                        case 1:
                        case 3:
                        case 5:
                        case 7:
                        case 8:
                        case 10:
                            dNum += 31;
                            m--;
                            break;
                        case 2:
                            dNum += 29;
                            m--;
                            break;
                        case 4:
                        case 6:
                        case 9:
                        case 11:
                            dNum += 30;
                            m--;
                            break;
                    }
                }
            } else {
                while (m > 1) {
                    switch (m - 1) {
                        case 1:
                        case 3:
                        case 5:
                        case 7:
                        case 8:
                        case 10:
                            dNum += 31;
                            m--;
                            break;
                        case 2:
                            dNum += 28;
                            m--;
                            break;
                        case 4:
                        case 6:
                        case 9:
                        case 11:
                            dNum += 30;
                            m--;
                            break;
                    }
                }
            }
            dNum += d;
            System.out.println(dNum);
        }
    }
}