C语言_打印回型矩阵BC133

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdlib.h>
int main()
{
	int n = 0;
	int arr[20][20]; 
	scanf("%d", &n);
	int up = 0, left = 0, right = n - 1, down = n - 1;
	 int a = 1;
	while (a <= n*n)
	{
		for (int j = left; j <= right; j++)//上
		{
			arr[up][j] = a++;
		}up++;
		for (int l = up; l <= down; l++)//右
		{
			arr[l][right] = a++;
		}right--;
		for (int j = right; j >= left; j--)//下
		{
			arr[down][j] = a++;
		}down--;
		for (int j = down; j >= up; j--)//左
		{
			arr[j][left] = a++;
		}left++;
	}
	for (int x = 0; x < n; x++)//打印
	{                   
		for (int j = 0; j < n; j++)
		{
			printf("%3d ", arr[x][j]);
		}
		puts("");
	}
	return 0;
}