Xiaoming who is good at arranging

Xiaoming who is good at arranging

Time Limit: 1000 ms | Memory Limit: 65535 KB

Difficulty: 4

describe

Xiao Ming is very smart and very good at permutation calculations. For example, if you give Xiao Ming a number 5, he can immediately give the full arrangement of 1-5 in lexicographical order. If you want to embarrass him, choose a few numbers from these 5 numbers and let him continue to arrange the full arrangement, then you are wrong. , he is equally good at it. Now you need to write a program to verify whether Xiao Ming, who is good at permutation, is right.

enter

The first line of input integer N (1<N<10) indicates how many sets of test data,
each set of test data has two integers nm in the first line (1<n<9,0<m<=n)

output

Select m characters from 1-n for full arrangement, and output them all in lexicographical order, each arrangement occupies one line, and there is no need to divide each group of data. as example

sample input

2
3 1
4 2

Sample output

1
2
3
12
13
14
21
23
24
31
32
34
41
42
43

code show as below:

#include<cstdio>
using namespace std;

const int maxn=101;
int p[maxn];
int n,m;
bool hashTable[maxn]={false};

void DFS(int index){
    if(index>=m+1){
        for(int i=1;i<=m;i++)
            printf("%d",p[i]);
        printf("\n");
        return;
    }
    for(int i=1;i<=n;i++){
        if(hashTable[i]==false){
            p[index]=i;
            hashTable[i]=true;
            DFS(index+1);
            hashTable[i]=false;
        }
    }
}
int main()
{
    int N;
    scanf("%d",&N);
    while(N--){
        scanf("%d %d",&n,&m);
        DFS(1);
    }
    return 0;
}