CF 12E Start of the season

E - Start of the season

Crawling in process...Crawling failedTime Limit:2000MS    Memory Limit:262144KB   64bit IO Format:%I64d & %I64u

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Description

Before the start of the football season in Berland a strange magic ritual is held. The most experienced magicians have to find a magic matrix of the sizen × n (n is even number). Gods will never allow to start the championship without it. Matrix should contain integers from0 ton - 1, main diagonal should contain only zeroes and matrix should be symmetric. Moreover, all numbers in each row should be different. Magicians are very tired of the thinking process, so they ask you to write a program to find such matrix.

Input

<p< p="">

The first line contains one integer n (2 ≤ n ≤ 1000),n is even.

Output

<p< p="">

Output n lines with n numbers each — the required matrix. Separate numbers with spaces. If there are several solutions, output any.

Sample Input

Input
2
Output
0 1
1 0
Input
4
Output
0 1 3 2
1 0 2 3
3 2 0 1
2 3 1 0

很好的想法题,我们的焕神思维很强大,借用一下。

重点是不要把0考虑进去。

假如n=4

我们可以进行全排列

1 2 3

2 3 1

3 1 2

每一行,每一列还缺少一个0,所以我们会得到如下矩阵

1 2 3 0

2 3 1 0

3 1 2 0

0 0 0 0

所以我们直接把主对角线的序列抽出来得到1 3 2 ,分别填充到最后一行和最后一列就会得到满足题意的如下矩阵

0 2 3 1

2 0 1 3

3 1 0 2

1 3 2 0

代码如下:

#include<iostream>
#include<cstdlib>
#include<stdio.h>
#include<map>
#include<algorithm>
#include<string.h>
using namespace std;
int f[1010][1010];
int main()
{
    int n;
    int g[1010];
    while(scanf("%d",&n)!=EOF)
    {
       int num=1;
       for(int i=0;i<n-1;i++)
       {
           int j=0;
           int pi=i;
           while(pi>=0&&j<n-1)
           {
               f[pi][j]=num;
               pi--;j++;
           }
           num++;
           if(num>=n) num=1;
       }


       for(int j=1;j<n-1;j++)
       {
           int pj=j;
           int i=n-2;
           while(i>=0&&pj<n-1)
           {
               f[i][pj]=num;
               i--;pj++;
           }
           num++;
           if(num>=n) num=1;
       }

       for(int i=0;i<n-1;i++)
       g[i]=f[i][i];

      /* for(int i=0;i<n-1;i++)
       for(int j=0;j<n-1;j++)
       {
           cout<<f[i][j]<<" ";
           if(j==n-2)
           cout<<endl;
       }
     */

       for(int i=0;i<n;i++)
       for(int j=0;j<n;j++)
       {
           if(i==j)
           {
               if(j==0)
               cout<<0;
               else cout<<" "<<0;
           }
           else if(i==n-1)
           {
               if(j==0)
               cout<<g[j];
               else
               cout<<" "<<g[j];
           }
           else if(j==n-1)
           {
               cout<<" "<<g[i];
           }
           else
           {
           if(j==0)
           cout<<f[i][j];
           else cout<<" "<<f[i][j];
           }
           if(j==n-1) cout<<endl;

       }
    }
}


 

 

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