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>
                            #include<iostream>
                            #include<cstdio>
                            #include<vector>
                            #include<queue>
                            #include<map>
                            #include<cstring>
                            #include<string>
                            #include <math.h>
                            #include<algorithm>
                        //    #include <boost/multiprecision/cpp_int.hpp>
                            #include<functional>
                 //    #define int long long
                            #define inf  1000000007
                            #define pa pair<int,int>
                            #define ll long long
                            #define pal pair<double,int>
                            #define ppa pair<pa,int>
                            #define ppap pair<int,pa>
                            #define ssa pair<string,int>
                            #define  mp make_pair
                            #define  pb push_back
                            #define EPS (1e-10)
                            #define equals(a,b) (fabs((a)-(b))<EPS)
                     
                            using namespace std;
                     //priority_queue<int, vector<int>, greater<int> > que;
                            class Point{
                            	public:
                            	double x,y;
                            	Point(double x=0,double y=0):x(x),y(y) {}
                            	Point operator + (Point p) {return Point(x+p.x,y+p.y);}
                            	Point operator - (Point p) {return Point(x-p.x,y-p.y);}
                            	Point operator * (double a) {return Point(x*a,y*a);}
                            	Point operator / (double a) {return Point(x/a,y/a);}
                            	double absv() {return sqrt(norm());}
                            	double norm() {return x*x+y*y;}
                            	bool operator < (const Point &p) const{
                            		return x != p.x ? x<p.x: y<p.y;
                            	}
                            	bool operator == (const Point &p) const{
                            		return fabs(x-p.x)<EPS && fabs(y-p.y)<EPS;
                            	}
                            };
                            typedef Point Vector;
                     
                            struct Segment{
                            Point p1,p2;
                            };
                     
                        double hen(Vector a){
                        if(fabs(a.x)<EPS && a.y>0) return acos(0);
                        else if(fabs(a.x)<EPS && a.y<0) return 3*acos(0);
                        else if(fabs(a.y)<EPS && a.x<0) return 2*acos(0);
                        else if(fabs(a.y)<EPS && a.x>0) return 0.0;
                        else if(a.y>0) return acos(a.x/a.absv());
                        else return 2*acos(0)+acos(-a.x/a.absv());
                     
                        }
                     
                string itos( int i ) {
                ostringstream s ;
                s << i ;
                return s.str() ;
                }
                 
                int gcd(int v,int b){
                	if(v>b) return gcd(b,v);
                	if(v==b) return b;
                	if(b%v==0) return v;
                	return gcd(v,b%v);
                }
                            double dot(Vector a,Vector b){
                            	return a.x*b.x+a.y*b.y;
                            }
                            double cross(Vector a,Vector b){
                            	return a.x*b.y-a.y*b.x;
                            }
                        
                double distans(double x1,double y1,double x2,double y2){
                	double rr=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
                	return sqrt(rr);
                	
                }
                /*}
int pr[100010];
//int inv[100010];
 
int beki(int wa,int rr){
	if(rr==0) return 1ll;
	if(rr==1) return wa;
	if(rr%2==1) return (beki(wa,rr-1)*wa)%inf;
	int zx=beki(wa,rr/2);
	return (zx*zx)%inf;
}
  
void gya(){
	pr[0]=1;
	for(int i=1;i<100010;i++){
		pr[i]=(pr[i-1]*i)%inf;
	}
	for(int i=0;i<100010;i++) inv[i]=beki(pr[i],inf-2);
	
}

*/

                         //----------------kokomade tenpure------------


signed main(){
	int n;
	while(1){
	cin>>n;
		if(n==0) return 0;
		vector<int> ve;
		
		for(int i=0;i<n;i++) {
			int k;
			cin>>k;
			
			ve.pb(k);
		}
		sort(ve.begin(),ve.end());
		int u=10000000;
		for(int i=0;i<n-1;i++) u=min(u,ve[i+1]-ve[i]);
		cout<<u<<endl;
	}
	
	
	return 0;
}

C++: #include <iostream>
#include <string>
using namespace std;

int main(){
        int a[50000];
        int i,j,min,sa,n;
        while(1) {
                cin>>n;

                if(n==0) {
                        break;
                }

                for(i=0; i<n; i++) {
                        cin>>a[i];
                }

                min=1000000;

                for(i=0; i<n; i++) {
                        for(j=0; j<n; j++) {
                                if(i!=j) {
                                        if(a[i]>a[j]) {
                                                sa=a[i]-a[j];
                                        }else{
                                                sa=a[j]-a[i];
                                        }

                                        if(min>sa) {
                                                min=sa;
                                        }
                                }
                        }
                }

                cout<<min<<endl;
        }

}

C++: #include <iostream>
using namespace std;

int main(){
	while(1){
		int n;
		cin >> n;
		if(n==0)break;

		int a[1000];
		for(int i=0;i<n;i++){
			cin >> a[i];
		}

		int dif = 1000001;
		for(int i=0;i<n-1;i++){
			for(int j=i+1;j<n;j++){
				int d = abs(a[i]-a[j]);
				if(d<dif)dif=d;
			}
		}

		cout << dif << endl;
	}

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> mp;
#define inf 1e9


int main(){

	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(a.begin(),a.end());
		int m = 1e9;
		for(int i=0;i<n-1;i++)m = min(m,a[i+1]-a[i]);
		cout<<m<<endl;
	}

	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
int main(int argc, char *argv[])
{
        for(;;) {
                int n;
                cin >> n;
                if(n==0) break;
                vector<int> vs;
                for(int i = 0; i < n; i++) {
                        int k;
                        cin >> k;
                        vs.push_back(k);
                }
                sort(vs.begin(), vs.end());
                int a = abs(vs[0]-vs[1]);
                for(int i = 0; i < n-1; i++) a = min(a, abs(vs[i]-vs[i+1]));
                cout << a << endl;
        }
        return 0;
}