B. Honest Coach.cpp

#include<bits/stdc++.h>
 
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair <int,int> pii;
typedef pair <ll,ll> pll;
 
///#define ff              first
///#define ss              second
///#define pb              push_back
///#define all(v)          v.begin(),v.end()
 
///#define D(x)            cerr << #x " = " << x << '\n'
///#define DBG             cerr << "Hi!" << '\n'
 
///#define CLR(a)          memset(a,0,sizeof(a))
///#define SET(a)          memset(a,-1,sizeof(a))
///#define nn              "\n"
///#define gcd(a,b)        __gcd(a,b)
///#define lcm(a,b)        (a*b)/gcd(a,b)
///#define	pi             acos(-1.0)
#define inf             2e9+10
 
//const double pi = acos(-1.0);
//const double eps = 1e-8;
 
void solve(){
    int t;
    cin>>t;
    while(t--){
        int n,arr[1000],mn=inf;
        cin>>n;
        for(int i=0;i<n;i++){
            cin>>arr[i];
        }
        sort(arr,arr+n);
        for(int i=n-1;i>0;i--){
            int x=arr[i]-arr[i-1];
            mn=min(mn,x);
        }
        cout<<mn<<"\n";
    }
}
 
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
 
    //freopen("in.txt", "r", stdin);
 
    solve();
 
 
    return 0;
}