chinese zodiac signs_icpc铜奖

2
3 1
4 3

Impossible
2 1 4 3
3 4 1 2
4 3 2 1

#include<bits/stdc++.h>
using namespace std;
const int N = 1001;
int ch[N][N];
int lowbit(int x){ 
   
    return x & (-x);
}

int main(){ 
   
    int n,k;
    int T;
    cin>>T;
    while(T --){ 
   
        cin>>n>>k;
        
        if(k >= lowbit(n))cout<<"Impossible"<<endl;
        else{ 
   
            for(int i = 1;i <= n;i ++){ 
   
                ch[0][i] = i;
            }
            
            for(int t = 1;t <= k;){ 
   
                for(int k = t;k < 2 * t;k ++){ 
   
                    int offset = t;
                    for(int z = 1;z <= n;z += 2 * offset){ 
   
                        for(int j = z;j < z + offset;j ++){ 
   
                            ch[k][j] = ch[k - offset][j + offset];
                        }
                        for(int j = z + offset;j < z + 2 * offset;j ++){ 
   
                            ch[k][j] = ch[k - offset][j - offset];
                        }
                    }
                    
                }
                
                t *= 2;
            }
            for(int i = 1;i <= k;i ++){ 
   
                cout<<ch[i][1];
                for(int j = 2;j <= n;j ++){ 
   
                    cout<<" " << ch[i][j];
                }
                cout<<endl;
            }
        }
    }
    return 0;
}