链接:https://www.nowcoder.com/acm/contest/142/D
来源:牛客网
题目描述
Chiaki has an n x n matrix. She would like to fill each entry by -1, 0 or 1 such that r1,r2,...,rn,c1,c2, ..., cn are distinct values, where ri be the sum of the i-th row and ci be the sum of the i-th column.
输入描述:
There are multiple test cases. The first line of input contains an integer T (1 ≤ T ≤ 200), indicating the number of test cases. For each test case: The first line contains an integer n (1 ≤ n ≤ 200) -- the dimension of the matrix.
输出描述:
For each test case, if no such matrix exists, output ``impossible'' in a single line. Otherwise, output ``possible'' in the first line. And each of the next n lines contains n integers, denoting the solution matrix. If there are multiple solutions, output any of them.
示例1
输入
2 1 2
输出
impossible possible 1 0 1 -1
题目大意:用0 1 -1 构造一个n*n的矩阵使每行每列的值都不相同。
思路:n*n的矩阵 可以用0 1 -1 构造出2*n+1个值 无论怎么选端点的值一定能够取到。
先把每行都赋值为1或-1呈三角形,再挑出位置赋值0
#include<iostream>
#include<cstdio>
using namespace std;
#define sca(x) scanf("%d",&x)
#define rep(i,j,k) for(int i=j;i<=k;i++)
int a[205][205];
int main()
{
int t;
sca(t);
while(t--)
{
int n;sca(n);
if(n&1)printf("impossible\n");
else
{
printf("possible\n");
rep(i,1,n)
rep(j,1,n)
{
if(j<=i)a[i][j]=1;
else a[i][j]=-1;
if(j==i&&i&1)a[i][j]=0;
}
rep(i,1,n)
rep(j,1,n)
{
printf("%d%c",a[i][j],j==n?'\n':' ');
}
}
}
}