Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

const (
	initialBufSize = 1e4
	maxBufSize     = 1e6 + 7
)

var buf []byte = make([]byte, maxBufSize)
var sc = bufio.NewScanner(os.Stdin)

func init() {
	sc.Split(bufio.ScanWords)
	sc.Buffer(buf, maxBufSize)
}

func main() {
	for {
		n := nextInt()
		if n == 0 {
			break
		}
		an := make([]int, n)
		min := 1000000
		for i := 0; i < n; i++ {
			an[i] = nextInt()
		}
		sort.Ints(an)
		for i := 1; i < n; i++ {
			sub := an[i] - an[i-1]
			if min > sub {
				min = sub
			}
		}
		fmt.Println(min)
	}
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define all(x) (x).begin(),(x).end()
const int mod=998244353,MAX=100005,INF=1<<28;

int main(){
    
    std::ifstream in("text.txt");
    std::cin.rdbuf(in.rdbuf());
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    while(1){
        int N;cin>>N;
        if(N==0) break;
        vector<int> A(N);
        for(int i=0;i<N;i++) cin>>A[i];
        sort(all(A));
        
        int ans=INF;
        
        for(int i=1;i<N;i++) ans=min(ans,A[i]-A[i-1]);
        
        cout<<ans<<endl;
    }
}

C++: 
using namespace std;
typedef long long ll;
#include <string>
#include <vector>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <map>/*
#define out(S) cout<<(S)<<endl;
#define mod(i) ((i)%(ll)(1000000000 + 7))
ll modpow(ll i, ll j) { ll tmp = 1; while (j) { if (j % 2)tmp = mod(tmp*i); i = mod(i*i); j /= 2; }return tmp; }
#define divmod(a,b) (mod(a * modpow((ll)b,(ll)(1e9+5))))
#define For(i,a,b) for(size_t i=(a);i<(b);i++)
#define rFor(i,a,b) for(size_t i=(a)-1;i>=(b);i--)
#define Rep(i,a) for(size_t i=0;i<(a);i++)
#define rRep(i,a) for(size_t i=(a)-1;i>=0;i--)
#define Foreach(item,collection) for(auto item:collection)*/

int main(){
	int N;
	cin >> N;
	vector<ll> ans;
	while (N!=0)
	{
		vector<ll> a;
		a.resize(N);
		for (int i = 0; i < N; i++) cin >> a[i];
		ll thismin = 1e10;
		for (int i = 0; i < N;i++) {
			for (int n = 0; n < N; n++) {
				if (n == i) continue;
				thismin = min(thismin, abs(a[i] - a[n]));
			}
		}
		ans.push_back(thismin);
		cin >> N;
	}
	for (auto i : ans) {
		cout << i << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<utility>
#include<set>
#include<complex>
#define vi vector<int>
#define vvi vector<vector<int> >
#define ll long long int
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
#define ld long double
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define CC puts("-------ok--------");
#define all(in) in.begin(), in.end()
#define bv vector<bool>
using namespace std;
typedef pair<int, int> PI;
#define MAX 99999999
int main(){
    int n;
    while(cin>>n,n) {
        vi v(n);rep(i,n)cin>>v[i];
        sort(v.begin(), v.end());
        int ans=INF;
        for(int j=0; j<n-1;j++) ans=min(abs(v[j]-v[j+1]),ans);
        cout<<ans<<endl;
    }
}

C++: #include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for (int i=0; i<(n); ++i)
#define RREP(i, n) for (int i=(int)(n)-1; i>=0; --i)
#define FOR(i, a, n) for (int i=(a); i<(n); ++i)
#define RFOR(i, a, n) for (int i=(int)(n)-1; i>=(a); --i)

#define SZ(x) ((int)(x).size())
#define all(x) begin(x),end(x)

#define dump(x) cerr<<#x<<" = "<<(x)<<endl
#define debug(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;

template<class T>
ostream &operator<<(ostream &os, const vector <T> &v) {
    os << "[";
    REP (i, SZ(v)) {
        if (i) os << ", ";
        os << v[i];
    }
    return os << "]";
}

template<class T, class U>
ostream &operator<<(ostream &os, const pair <T, U> &p) {
    return os << "(" << p.first << " " << p.second << ")";
}

template<class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;
using vvi = vector <vector<int>>;
using vvll = vector <vector<ll>>;

#define inf(T) (numeric_limits<T>::max() / 2)
const ll MOD = 1e9 + 7;
const ld EPS = 1e-9;


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    for (;;) {
        int n; cin >> n;
        if (n == 0) break;

        vi a(n);
        REP(i, n) cin >> a[i];
        sort(all(a));

        int ans = inf(int);
        REP(i, n-1) chmin(ans, a[i+1] - a[i]);

        cout << ans << endl;
    }

    return 0;
}