给定年月日计算是那一天

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public class Day {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        while (input.hasNext()){
            int year = input.nextInt();
            int month = input.nextInt();
            int day = input.nextInt();
            int daysInYear = getDaysInYear(year, month, day);
            System.out.println(daysInYear);
        }
    }

    private static int getDaysInYear(int year, int month, int day) {

        int total = 0;

        switch (month-1){
            case 11:total += 30;
            case 10:total += 31;
            case 9:total += 30;
            case 8:total += 31;
            case 7:total += 31;
            case 6:total += 30;
            case 5:total += 31;
            case 4:total += 30;
            case 3:total += 31;
            case 2:total += 28;
            case 1:total += 31;
            case 0:break;
        }
        if (isR(year)){
            total++;
        }
        total +=day;
        return total;
    }

    private static boolean isR(int year){
        if(year%400==0||(year%4==0 && year%100!=0)){
            return true;
        }
        return false;
    }

}

计算回文素数

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public class Sushu {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = in.nextInt();
        int b = in.nextInt();

        for (int i=a;i<=b;i++){
            if (isPrime(i) && isHuiO(i)){
                System.out.println(i);
            }
        }
    }
    //判断是不是素数
    private static boolean isPrime(int n){
        for (int i = 2;i<Math.sqrt(n);i++){
            if (n % i ==0){
                return false;
            }
        }
        return true;
    }

    private static boolean isHuiO(int n){
        String s = String.valueOf(n);
        for (int i = 0;i<s.length()/2;i++){
            if (s.charAt(i)!=s.charAt(s.length()-i-1)){
                return false;
            }
        }
        return true;
    }
}