#include <iostream>
using namespace std;

long maximum(long a,long b)
{
    if(a>b)
      return a;
    else
      return b;
}

long modd(long a)
{
    if(a<0)
      return -a;
    else
      return a;
}
int main() {
	
	long t;
	cin>>t;
	for(long i=0;i<t;i++)
	{
	    long n,m;
	    cin>>n>>m;
	    long leftMax=0,rightMax=0;
	    for(long j=0;j<m;j++)
	    {
	        long input;
	        cin>>input;
	        if(input>leftMax)
	           leftMax=input;
	        if(n-input-1>rightMax)
	           rightMax=n-input-1;
	    }
	    if(n==1)
	      cout<<leftMax<<"\n";
	    else
	    {
	      cout<<leftMax;
	      for(long j=1;j<n-1;j++)
	      {
	          cout<<maximum(modd(leftMax-j),modd(rightMax-(n-j-1)));
	      }
	      cout<<rightMax<<"\n";
	    }
	}
	return 0;
}