蓝桥杯，第五天java打卡

public class Main {
    public static void main(String[] args) {
        for(int i =100;;i++){
            int n = i;
            if(n>0&&n%5 == 1){
                n = n - n/5 - 1;
            }else continue;

            if(n>0&&n%5 == 2){
                n = n - n/5 - 2;
            }else continue;

            if(n>0&&n%5 == 3){
                n = n - n/5 - 3;
            }else continue;

            if(n>0&&n%5 == 4){
                n = n - n/5 - 4;
            }else continue;

            if(n>0&&n%5 == 0){
                System.out.println(i);
                break;
            }
        }
    } 
}

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int min=0;
        Scanner sc = new Scanner(System.in);
        int number = sc.nextInt();
        int[] a = new int[number];
        int length = a.length-1;
        for(int j = 0;j<number;j++) a[j] = sc.nextInt();
        //排序后的数组
        sort(a, 0, length);
        //特殊情况
        if(a[0] == a[length]) System.out.println(number);

        else {
            //求最小的公倍数
            for(int k =1;k<length+1;k++)
                min = gcd(min, a[k]-a[k-1]);

            System.out.println((a[length]-a[0])/min+1);
        }
        
        
    }
    //快速排序
    static void sort(int[] num, int left, int right){
        if(left>right)return;
        int i,j,temp,t;
        i = left;
        j = right;
        //temp为基准位
        temp = num[left];
        while(i<j){
            //先右边
            while(temp<=num[j]&&i<j)j--;
            //再左边
            while(temp>=num[i]&&i<j)i++;
            //如果满足条件则交换
            if (i<j) {
                t = num[j];
                num[j] = num[i];
                num[i] = t;
            }
        }
            //最后将基准为与i和j相等位置的数字交换
            num[left] = num[i];
            num[i] = temp;
            //递归调用左半数组
            sort(num, left, j-1);
            //递归调用右半数组
            sort(num, j+1, right);

        

    }

    static int gcd(int a, int b){ 
        if(b==0)return a;
        return gcd(b, a % b) ;
    }
}

暴力破解，哈哈

public class Main {
    public static void main(String[] args) {
        for(int x = 2019;x<10000;x++){
            for(int y = x+1;y<10000;y++){
                if(y*y-x*x == x*x-2019*2019){
                    System.out.println(x+y);
                    return;
                    
                }
            }
        }
    }
    
}