min_element.cpp

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>

#define INF 9999999
#define MAX 1000000

typedef long long ll;

using namespace std;
int n,t;
ll tab[MAX];

int main() {
   	cin>>n;
	while(n--){
		
		cin>>t;
		for(int i=0;i<t;i++){
			cin >> tab[i];
		}
		
		sort(tab, tab + t);
		int min = INF;
		for(int i = 0; i < t - 1; i++){
			if(abs(tab[i] - tab[i+1]) < min)
				min = abs(tab[i] - tab[i+1]);
		}
		
		cout << min << endl;
	}
   	
   	return 0;
}