#include <stdio.h>#include <algorithm>#include <stdlib.h>#include <set>#include <iostream>#include <map>#include <cmath>using namespace std;/*int cmp( const void *a, const void *b) { return *(int *)a-*(int *)b;}*/int main(){ int T; while( ~scanf("%d", &T) ) while(T--) { int n,k; scanf("%d %d", &n, &k ); int num[1010]; set <int > result; for(int i=1; i<=n; i++) scanf("%d", &num[i] ); for(int i=1; i<n; i++) { for(int j=i+1; j<=n ;j++) result.insert(abs(num[i]-num[j] ) ); } std::set<int>::iterator it; int count=0; /*for(it = result.begin(); it!=result.end(); it++) { if( ++count == k) cout << *it << endl; }*/ it = result.begin(); it = it + k; }}