7次WA终于过了的100行JAVA代码

import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        int y=0;
        int n=0;
        int[] month=new int[]{31,28,31,30,31,30,31,31,30,31,30,31};
        while(sc.hasNext()){
            y=sc.nextInt();
            n=sc.nextInt();
            int mon=0;
            int day=0;
            if(!isTrueYear(y)){
                if(n>=1&&n<=31){
                    mon=1;
                    day=n;
                }else if(n>31&&n<=59){
                    mon=2;
                    day=n-31;
                }else if(n>59&&n<=90){
                    mon=3;
                    day=n-59;
                }else if(n>90&&n<=120){
                    mon=4;
                    day=n-90;
                }else if(n>120&&n<=151){
                    mon=5;
                    day=n-120;
                }else if(n>151&&n<=181){
                    mon=6;
                    day=n-151;
                }else if(n>181&&n<=212){
                    mon=7;
                    day=n-181;
                }else if(n>212&&n<=243){
                    mon=8;
                    day=n-212;
                }else if(n>243&&n<=273){
                    mon=9;
                    day=n-243;
                }else if(n>273&&n<=304){
                    mon=10;
                    day=n-273;
                }else if(n>304&&n<=334){
                    mon=11;
                    day=n-304;
                }else if(n>334&&n<=365){
                    mon=12;
                    day=n-334;
                }
            }else{
                if(n>=1&&n<=31){
                    mon=1;
                    day=n;
                }else if(n>31&&n<=60){
                    mon=2;
                    day=n-31;
                }else if(n>60&&n<=91){
                    mon=3;
                    day=n-60;
                }else if(n>91&&n<=121){
                    mon=4;
                    day=n-91;
                }else if(n>121&&n<=152){
                    mon=5;
                    day=n-121;
                }else if(n>152&&n<=182){
                    mon=6;
                    day=n-152;
                }else if(n>182&&n<=213){
                    mon=7;
                    day=n-182;
                }else if(n>213&&n<=244){
                    mon=8;
                    day=n-213;
                }else if(n>244&&n<=274){
                    mon=9;
                    day=n-244;
                }else if(n>274&&n<=305){
                    mon=10;
                    day=n-274;
                }else if(n>305&&n<=335){
                    mon=11;
                    day=n-305;
                }else if(n>335&&n<=366){
                    mon=12;
                    day=n-335;
                }
            }
            if(mon<10){
                if(day<10){
                    System.out.println(y+"-0"+mon+"-0"+day);
                }else{
                    System.out.println(y+"-0"+mon+"-"+day);
                }
            }else{
                if(day<10){
                    System.out.println(y+"-"+mon+"-0"+day);
                }else{
                    System.out.println(y+"-"+mon+"-"+day);
                }
            }
        }

    }

    static boolean isTrueYear(int n){
        if(n%100==0){
            if(n%400==0)return true;
            else return false;
        }
        else if(n%4==0){
            return true;
        }else{
            return false;
        }
    }
}