Java学习-练习-Day01

题目来源：《疯狂Java讲义》

第一题

package study;

public class ArrayTest {
    public static void main (String[] args){
       int[] arr = {1,2,3,4,5,6,7,8,9};
        for (int i: arr ) {
            for (int j=1;j <= i;j++) {
                if(j > 1){System.out.print(',');}
                System.out.print(i+" X "+j+" = "+i*j);
            }
            System.out.print('\n');
        }
    }
}

第二题

package study;

public class ArrayTest {
    public static void main (String[] args){
        System.out.println("输入4");
        int num = 4;
        int line = num * 2 - 1;
        for(int i = 0;i < num;i++){
            for(int j = 0;j < line;j++){
                int count = i * 2 + 1;
                int space = (line - count) / 2;
                if(j >= space && j < (space + count)){
                    System.out.print('*');
                }else{
                    System.out.print(' ');
                }
            }
            System.out.print('\n');
        }
    }
}

第六题

package study;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Gobang {
    private static int BOARD_SIZE = 15;
    private String[][] board;
    public void initBoard(){
        //初始化棋盘数组
        board = new String[BOARD_SIZE][BOARD_SIZE];
        //画出棋盘
        for(int i=0;i