CCF节日（Java）

方法一：硬算

import java.util.Scanner;
public class Main {
    static int y[] = new int[2051];
    static int m1[] = {0,31,28,31,30,31,30,31,31,30,31,30,31}; 
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        for(int i = 1850; i <= 2050; i++) {
            if(i%400==0||(i%4==0&&i%100!=0)) {
                y[i] = 1;
            }
        }
        int m = scanner.nextInt();
        int n = scanner.nextInt();
        int w = scanner.nextInt();
        int s = scanner.nextInt();
        int e = scanner.nextInt();
        for(int i = s;i<=e;i++) {
            int day = 0;
            for(int j =1850;j<i;j++) {
                day = day+365+y[j];
            }
            for(int j = 1; j < m;j++) {
                day+=m1[j];
                if(j==2) day+=y[i];
            }
            int ww = day%7+2;
            if(ww>7)ww = ww-7;
            int cnt = 0,flag = 0;
            int mm = (m==2?y[i]:0)+m1[m];
            for(int k = 1; k <= mm;k++) {
                if(w==ww)cnt++;
                if(cnt==n) {
                    flag =k;
                    break;
                }
                ww = ww+1==8?1:ww+1;
            }
            if(flag == 0) System.out.println("none");
            else System.out.println(String.format("%d/%02d/%02d", i,m,flag));
            
        }
    }
}

方法二：JavaAPI

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Scanner;
public class Main {
    static int mm[] = {0,31,28,31,30,31,30,31,31,30,31,30,31}; 
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int m = scanner.nextInt();
        int n = scanner.nextInt();
        int w = scanner.nextInt();
        int s = scanner.nextInt();
        int e = scanner.nextInt();
        DateTimeFormatter f = DateTimeFormatter.ofPattern("yyyy/MM/dd");
        for(int i = s; i <= e; i++) {
            String q = String.format("%d/%02d/%02d", i,m,1);
            LocalDate ldt = LocalDate.parse(q, f);
            int ww = ldt.getDayOfWeek().getValue();
            mm[2] = ldt.isLeapYear()?29:28;
            int cnt = 0;
            int k = 1+(w+7-ww);
            if(k>7) k-=7;
            while(k<=mm[m]) {
                cnt++;
                if(cnt==n) {
                    System.out.println(String.format("%d/%02d/%02d", i,m,k));
                    break;
                }
                k+=7;
            }
            if(k>mm[m])System.out.println("none");
        }
        
    }
}