蛇形填数

描述在n*n方陈里填入1,2,...,n*n,要求填成蛇形。例如n=4时方陈为：
10 11 12 1
9 16 13 2
8 15 14 3
7 6 5 4

 

输入

直接输入方陈的维数，即n的值。(n<=100)

输出

输出结果是蛇形方陈。

样例输入

3

样例输出

7 8 1
6 9 2
5 4 3

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int n;
        int flag[][]=new int[101][101];
        int i;
        int j;
        int count;
        String direction;
        
        n=scanner.nextInt();
        
        for(i=0;i<n;i++){
            for(j=0;j<n;j++)
                flag[i][j]=0;
        }
        
        i=0;
        j=n-1;
        direction="south";
        count=1;
        
        while(true){
            flag[i][j]=count;
            count++;

            if(direction.compareTo("south")==0){
                i++;
                
                if(i==n || flag[i][j]!=0){
                    direction="west";
                    i--;
                    j--;
                }
            }
            
            else if(direction.compareTo("west")==0){
                j--;
                
                if(j==-1 || flag[i][j]!=0){
                    direction="north";
                    j++;
                    i--;
                }
            }
            
            else if(direction.compareTo("north")==0){
                i--;
                
                if(i==-1 || flag[i][j]!=0){
                    direction="East";
                    i++;
                    j++;
                }
            }
            
            else if(direction.compareTo("East")==0){
                j++;
                
                if(j==n || flag[i][j]!=0){
                    direction="south";
                    j--;
                    i++;
                }
            }
            
            if(count==n*n+1)
                break;
        }
        
        for(i=0;i<n;i++){
            for(j=0;j<n;j++)
                System.out.print(flag[i][j]+" ");
        
            System.out.println();
        }
    }
}