Go: package main

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

var infty = 100000 * 2
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() (int, error) {
	scanner.Scan()
	return strconv.Atoi(scanner.Text())
}

func findMaximumSubarray(arr []int) int {
	currentMaxSum, maxSumContainsTail := -infty, -infty

	for j := range arr {
		if arr[j] > maxSumContainsTail+arr[j] {
			maxSumContainsTail = arr[j]
		} else {
			maxSumContainsTail += arr[j]
		}
		if currentMaxSum < maxSumContainsTail {
			currentMaxSum = maxSumContainsTail
		}

		// fmt.Println(arr[j], currentMaxSum, maxSumContainsTail)
	}
	return currentMaxSum
}

func main() {
	scanner.Split(bufio.ScanWords)
	for {
		size, _ := nextInt()
		if size == 0 {
			break
		}

		arr := make([]int, size)
		for i := range arr {
			n, _ := nextInt()
			arr[i] = n
		}

		maximumSum := findMaximumSubarray(arr)
		fmt.Println(maximumSum)
	}
}

C++: #include <bits/stdc++.h>
#define int long long
#define ll long long
#define rep(i,n) for(int i=0;i<n;i++)
#define INF (((ll)1<<31)-1)
#define eps LDBL_EPSILON
#define moder (1000000007)
#define pie 3.141592653589793238462643383279
#define P std::pair<int,int>
#define prique priority_queue
#define ggr getchar();getchar();return 0;
using namespace std;
int n,a[5010],b[5010];
signed main(){
	while(true){
		cin>>n;
		if(!n)break;
		rep(i,n){
			cin>>a[i];
			if(i)a[i]+=a[i-1];
		}
		rep(i,n){
			if(i)b[i]=min(b[i-1],a[i]);
			else b[i]=min((ll)0,a[i]);
		}
		int ans=-INF;
		rep(i,n){
			ans=max(ans,a[i]-b[i-1]);
		}
		cout<<ans<<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>
#include<map>
#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 loop(i,s,n) for(int i=s;i<n;i++)
#define CC puts("-------ok--------");
#define all(in) in.begin(), in.end()
using namespace std;
typedef pair<int, int> pii;
#define MAX 99999999
int main(){
    int n;
    while(cin>>n,n){
        vi v(n+1,0);
        rep(i,n)cin>>v[i];
        ll ans=v[0], temp;
        for(int i=0;i<n;i++){
            temp=v[i];
            for(int j=i+1;j<n;j++){
                temp+=v[j];
                ans=max(ans,temp);
            }
        }
        cout<<ans<<endl;
    }
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cmath>
#include<list>
#include<stack>
#include<queue>
#include<cctype>
#include<iomanip>
#include<functional>
#include<numeric>
#define EPS 1e-10
#define INF (-(1<<21))
using namespace std;
typedef long long llong;
int main() {
	int n;
	while (1) {
		cin >> n;
		if (!n)break;
		vector<vector<int> >v(n, vector<int>(n));
		vector<int>a(n);
		for (int i = 0; i < n; i++)cin >> a[i];
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (i == j)v[i][j] = a[i];
				else v[i][j] = INF;
			}
		}
		int max = INF;
		for (int i = 0; i < n; i++) {
			for (int j = i; j < n; j++) {
				if (i == j) {
					//cout << v[i][j] << " ";
					continue;
				}
				v[i][j] = v[i][j - 1] + a[j];
				if (max < v[i][j])max = v[i][j];
				//cout << v[i][j] << " ";
			}
			//cout << endl;
		}
		cout << max << endl;
	}
	return 0;
}

C++: // 0022.cpp : コンソール アプリケーションのエントリ ポイントを定義します。
//
#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(ll a=0;a<t;a++) 
int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	ll n;
	while (cin >> n) {
		ll sum[5001];
		ll ans = -9000000000;
		roop(i, n) {
			cin >> sum[i];
			if (i != 0) { sum[i] += sum[i - 1]; }
			ans = max(ans, sum[i]);
		}
		for (ll i = 0; i < n - 1; i++) {

			ll	sumi = sum[i];

			for (ll j = i + 1; j < n; j++) {

				ll sumj = sum[j];
				ans = max(ans, sumj - sumi);
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
int main()
{
int n;
while(cin>>n&&n!=0)
{
int a[n];
int A=0;
int R=-100000;
for(int h=0;h<n;h++)
{
	cin>>a[h];
}
for(int i=0;i<n;i++)
{
	for(int j=0;j<n;j++)
	{
	for(int k=i;k<=j;k++)
	{
	//	cout << k << " ";		
		A=A+a[k];
		
	}	
	if(R<A)
	{
		R=A;
	}
//	cout<<endl;
	A=0;
	}
}
cout<<R<<endl;
}
return 0;
}

C++: 
#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <memory>
#include <string>

#include <algorithm>
#include <complex>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <vector>

using namespace std;

#ifdef _MSC_VER
#define __typeof__ decltype
#endif

#define ITER(c)         __typeof__((c).begin())
#define FOREACH(it, c)  for (ITER(c) it=(c).begin(); it != (c).end(); ++it)
#define RITER(c)        __typeof__((c).rbegin())
#define RFOREACH(it, c) for (RITER(c) it=(c).rbegin(); it != (c).rend(); ++it)
#define REP(i, n)       REPEAT(i, 0, n)
#define REPEAT(i, k, n) for (int i = (k); i < (n); ++i)
#define REVREP(i, n)    for (int i = ((n)-1); i >= 0; --i)
#define FIND(c, n)      std::find((c).begin(), (c).end(), (n));
#define BSEARCH(c, n)   std::binary_search((c).begin(), (c).end(), (n))
#define LLPOW(p1,p2)    ((ll)pow((double)(p1), (int)p2))
#define ESIZEOF(A)      (sizeof(A)/sizeof((A)[0]))
#define MIN(p1,p2)      (((p1)<(p2))?(p1):(p2))
#define MAX(p1,p2)      (((p1)>(p2))?(p1):(p2))
#define CIN_NO_SYNC     do { cin.tie(0); ios_base::sync_with_stdio(false); } while(0)
#define GETSTR(p)       fgets((p), sizeof(p), stdin)
#define CHOMP(p)        do{ char *_q = (p) + strlen(p)-1; if(*_q == '\n') *_q = 0; } while(0)

int main(){
    int n;
    while(cin >> n, n){
        int v[5001] = {0};
        int p = 0;
        int max = INT_MIN;
        REP(i, n){
            int in;
            cin >> in;
            REP(j, i+1){
                v[j] += in;
                max = MAX(max, v[j]);
                //printf("%d ", v[j]);
            }
            //printf("\n");
        }
        cout << max << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
int main(){
  int n;
  while( cin >> n ,n)
    {
      long long int a[5101] = {0};
      for(int i = 0 ; i < n ; i++ )
	{
	  cin >> a[i];
	}

      long long int dp[5101] = {0},mx = a[0];

      dp[0] = a[0];
      for(int i = 1 ; i < n ; i++ ){
	dp[i] = max(dp[i-1] + a[i],a[i]); 
	mx = max(dp[i],mx);
      }
      cout << mx << endl;
    }
  return 0;
}

C++: #include <iostream>
using namespace std;
int main (){
while (1){
long n,dset[5000],temp=0,MINEdset[5000],max,h[5000],b=0;
cin>>n;
if (n==0)break;
for (int i=0;i<n;i++){
        cin>>dset[i];
}
max=dset[0];
for (int i=0;i<n;i++){
        for (int j=i;j<n;j++){
                temp=temp+dset[j];
                MINEdset[j]=temp;
        }
        for (int j=i;j<n;j++){
                if (max<MINEdset[j]){
                        max=MINEdset[j];
                }
        }
        h[b]=max;
        b++;
        temp=0;
}
max=-99999;
for (int i=0;i<=b;i++){
        if (max<h[i]){
                max=h[i];
        }
}
cout<<max<<endl;
}
return 0;
}