JAva実験報告の最初の

import java.util.Scanner;

public class TheFirstDemo {

    public static void main(String[] args) {
        Scanner myinput = new Scanner(System.in);
        System.out.print("          ：");
        
        int col = myinput.nextInt();
        int i,j,k;
        for(i=1;i<=col;i++){
            for(j=1;j<=col-i;j++)
                System.out.print(" ");
            
            for(k=1;k<=i*2-1;k++){
                if(k%2==0)
                    System.out.print(" ");
                    else
                        System.out.print("@");
                
            }
            System.out.println();
        }
    }

}