题解 | #尼科彻斯定理#

莫名其妙

import java.math.*;
//import java.common-lang3;

public class Main{
    public static void main(String[]args){
        Scanner input = new Scanner(System.in);
        while(input.hasNextInt()){
            int a = input.nextInt();
            String[] ans = new String[2*a-1];
            int b = a*a;
            int hal = 0;
            int fir = 0;
            if(b%2 == 1){
                fir = b + 1 - a;
            }else{
                fir = b - a + 1;
            }
            ans[0] = String.valueOf(fir);

            for(int i = 1; i <= (a-1)*2; i=i+2){
                ans[i] = "+";
                ans[i+1] = String.valueOf(fir+ (i+1));
            }

            for(int i = 0; i < a*2-1; i++){
                System.out.print(ans[i]);
            }
            System.out.println();
        }
        
        
    }
}