JZOJsenior4323.【NOIP2015提高组Day1】神奇的幻方

problem

Description

Input

Output

Sample Input

3

Sample Output

8 1 6
3 5 7
4 9 2

Data Constraint

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analysis

真心希望明天的NOIPTG第一题像这题和NOIP2014的石头剪刀布这么水——
亏人家洛谷把这道签到题标上普及-的难度

题目都给了你方法求幻方，直接模拟就可以了，5分钟不到的码量……我也是醉了
时间复杂度$O(n)$

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code

#include<cstdio>

using namespace std;

int a[40][40];
int n;

int main()
{
    freopen("magic.in","r",stdin);
    freopen("magic.out","w",stdout);
    scanf("%d",&n);
    a[1][n/2+1]=1;
    int nowx=1,nowy=n/2+1;
    for (int i=2;i<=n*n;i++)
    {
        if (nowx==1 && nowy!=n)nowx=n,nowy+=1;
        else if (nowy==n && nowx!=1)nowy=1,nowx-=1; 
        else if (nowx==1 && nowy==n)nowx+=1;
        else if (nowx!=1 && nowy!=n)
        {
            if (a[nowx-1][nowy+1]==0)nowx-=1,nowy+=1;
            else nowx+=1;
        }
        a[nowx][nowy]=i;
    }
    for (int i=1;i<=n;i++)
    {
        for (int j=1;j<=n;j++)
        {
            printf("%d ",a[i][j]);
        }
        printf("\n");
    }
    return 0;
}