C/C++每日一题——蛇形填数

蛇形填数问题：输入一个整数n，按照蛇形填写n*n的矩阵

#include <iostream>
#include <iomanip>
#include <cstring>
using namespace std;
int main2()
{
	int n, x, y, total;
	cin >> n;
	int** a = new int* [n];//定义动态二维数组
	for (int i = 0; i < n; i++)
	{
		a[i] = new int[n];//按行分配空间
		memset(a[i], 0, n * sizeof(int));//将元素都赋值0
	}
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n; j++)
		{
			cout << setw(5) << a[i][j] ;//格式控制
		}
		cout << endl;
	}
	cout << endl;
	x = y = 0;
	total = a[0][0] = 1;
	while (total < n * n)
	{
		while (y + 1 < n && !a[x][y + 1])//向右
			a[x][++y] = ++total;
		while (x + 1 < n && !a[x+1][y])//向下
			a[++x][y] = ++total;
		while (y - 1 >=0 && !a[x][y - 1])//向左
			a[x][--y] = ++total;
		while (x-1>= 0 && !a[x-1][y])//向上
			a[--x][y] = ++total;
	}
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n; j++)
		{
			cout << setw(5) << a[i][j];
		}
		cout << endl;
	}
	for (int i = 0; i < n; i++)
		delete[] a[i];//按行释放空间
	delete[] a;
	return 0; 
}