Go: package main

import "fmt"

func main() {
	var result []int
	for {
		var n, a, maxSum int
		fmt.Scan(&n)

		if n == 0 {
			break
		}

		maxSum = 0
		sum := 0
		for i := 0; i < n; i++ {
			fmt.Scan(&a)
			if i == 0 {
				sum = a
				maxSum = sum
			} else if sum+a < a {
				sum = a
				if maxSum < sum {
					maxSum = sum
				}
			} else {
				sum = sum + a
				if maxSum < sum {
					maxSum = sum
				}
			}
		}

		result = append(result, maxSum)
	}

	for _, v := range result {
		fmt.Println(v)
	}
}

C++: #include<iostream>
#include<string.h>
#include<vector>
#include<list>
#include<stdio.h>
#include<math.h>
#include<iomanip>
#include<map>
#include<stack>
#include<queue>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) range(i,0,b)
#define debug(x) cout << "debug " << x << endl;
using namespace std;

int main(){
    int n;
    while(cin >> n, n){
        int plus[5000] = {0}, max = -100001, input;
        rep(i,n){
            cin >> input;
            plus[i]+= input;
            plus[i+1] = plus[i];
            if(max < plus[i]){
                max = plus[i];
            }
        }
        rep(i,n){
            rep(j,i-1){
                if(max < plus[i] - plus[j]){
                    max = plus[i] - plus[j];
                }
            }
        }
        cout << max << endl;
    }
}

C++: 
class Max
  def solve
    loop do
      n = gets.chomp.to_i
      break if n == 0
      
      max = -100000
      sum = 0
      n.times do
        a = gets.chomp.to_i
        sum += a
        if max < sum
          max = sum
        end
        if sum < 0 then 
          sum = 0
        end
      end
      puts max
    end
  end
end
Max.new.solve

C++: #include<stdio.h>
#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <iterator>
#include <list>
#include <map>     
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <iomanip>
#include <stack>
#include <string>
#include <vector>
using namespace std;
#define ll long long
#define ld long double
#define roop(a,t) for(int a=0;a<t;a++) 
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    while (cin >> n) {
        int sum[5001];
        roop(i, n) {
            cin >> sum[i];
            if (i != 0) { sum[i] += sum[i - 1]; }
        }
        int ans = -9000000000;
        for (int i = -1; i < n-1; i++) {
            int sumi = 0;
            if (i != -1)
            {
                sumi = sum[i];
            }
            for (int j = i + 1; j < n; j++) {
 
                int sumj = sum[j];
                ans = max(ans, sumj - sumi);
            }
        }
        cout << ans << endl;
    }
    return 0;
}

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

int main()
{
    while(1){
        int n,sum=0;
        cin>>n;
        if(n==0)
            break;
        int a[n];
        for(i=0;i<n;i++){
            cin>>a[i];
            sum+=a[i];
        }
        cout<<sum<<endl;
    }
    return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
#define ll long long
#define INF (1<<30)
int main() {
	cin.tie(0); ios::sync_with_stdio(false);
	int n;
	while (cin >> n, n) {
		vector<ll> a(n);
		vector<ll> Sum(n);
		for (int i = 0; i < n; i++) cin >> a[i];
		Sum[0] = a[0];
		for (int i = 1; i < n;i++) Sum[i] = a[i] + Sum[i - 1];

		ll ans = -INF;

		for (int i = 0; i < n;i++) {
			for (int j = i + 1;j < n;j++) {
				ans = max(ans,Sum[j] - Sum[i]);
			}
		}
		cout << ans << endl;
	}
}

C++: #include <iostream>
#include <algorithm>
#include <climits>
#include <vector>
using namespace std;
typedef vector <long> vlong;

long maxv(vlong &x){
	long tmp=x[0];
	for (int i=1; i<x.size(); i++)
		if (x[i]>tmp) tmp=x[i];
	return tmp;
}

int main(void){
	int n;
	vlong x;
	while (cin>>n){
		long s=LONG_MIN;
		if (n==0) break;
		for (int i=0; i<n; i++){
			long n2;
			cin>>n2;
			for (int j=0; j<x.size(); j++){
				x[j] += n2;
			}
			x.push_back(n2);
			if (i==0 || n2>0) s=max(s, maxv(x));
		}
		cout<<s<<endl;
		x.clear();
	}

	return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <cassert>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <set>
#include <map>
#include <bitset>
#include <functional>
#include <sstream>
#include <utility>
#include <cstdlib>
#include <cctype>
#include <climits>
#include <fstream>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<double> vd;
typedef vector<pair<int, int> > vpii;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) for(int i=0;i<(n);++i)
#define foreach(itr,c) for(__typeof(c.begin()) itr=c.begin(); itr!=c.end(); itr++)
#define dbg(x) cout << #x"="<< (x) << endl
#define mp(a,b) make_pair((a),(b))
#define pb(a) push_back(a) 
#define in(x) cin >> x;
#define all(x) (x).begin(), (x).end()
#define INF 2147483600
#define fi first
#define se second
using namespace std;

int main(){
	int N;
	int x;
	while(cin>>N&&N){
		int index=0;
		int ans = 0;
		int sum[5000+1];
		FOR(i,1,N+1){
			cin>>sum[i];
			sum[i] += sum[i-1];
		}
		FOR(i,1,N+1){
			FOR(j,i,N+1){
				ans = max(ans,sum[j]-sum[i-2]);
			}
		}
		cout<< ans <<endl;
	}
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <math.h>
#include <vector>
#include <set>

using namespace std;
typedef long long LL;
static const double EPS = 1e-9;

#define FOR(i,k,n) for (int i=(k); i<(int)(n); ++i)
#define REP(i,n) FOR(i,0,n) 

int main(void){  
  int n;
  while(cin>>n,n){
    int sum = 0, maxs = 0, a[10000];
    REP(i,n)
      cin >> a[i];
    FOR(i,0,n){
      sum += a[i];
      maxs = max(sum, maxs);
    }
    FOR(i,0,n){
      sum -= a[i];
      maxs = max(sum, maxs);
    }
    cout << maxs << endl;
  }
  return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <sstream>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <numeric>
#include <cmath>
#include <climits>
#include <limits>
#include <cfloat>
#include <fstream>
using namespace std;

int main()
{
//	cut here before submit 
//	freopen("testcase.mss", "r", stdin);
	string str = "";
	int n;

	while (1){
		getline (cin, str );
		stringstream ssn(str);
		ssn >> n;
		if (n == 0){
			break;
		} // end if
		vector <int> a(n, 0);
		int i,j;

		vector <int> sum (n, 0);

		for (i = 0; i < n; ++i){
			getline (cin, str );
			stringstream ss(str);
			ss >> a[i];
		} // end for
		for (i = 0; i < n; ++i){
			sum[i] = accumulate (a.begin(), a.begin()+i+1, 0 );
//			cout << "sum[" << i << "]:" << sum[i] << endl;
		} // end for

		int maxn = INT_MIN;
		for (i = 0; i < n; ++i){
			for (j = i + 1; j < n; ++j){
				 maxn = max (maxn , sum[j] - sum[i-1]);
			} // end for
		} // end for
		cout << maxn << endl;			

	} // end while

	return 0;
}