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 <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 sum[5001];
int main(){
	int N;
	int x;
	while(cin>>N&&N){
		int index=0;
		int ans = 0;
		
		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-1]);
			}
		}
		cout<< ans <<endl;
	}
}

C++: #include <cstdio>
#include <bitset>
#include <cmath>
#include <complex>
#include <vector>
#include <algorithm>
#include <stack>
#include <iostream>
#define EPS 1e-6

using namespace std;
typedef complex<double> coor;

double cross(coor a, coor b)
{
  return a.real() * b.imag() - a.imag() * b.real();
}

double dot(coor a, coor b)
{
  return a.real() * b.real() + a.imag() * b.imag();
}

int main()
{
  int N;
  while (scanf(" %d ", &N) == 1) {
    if (N == 0) {break;}
    vector<int> series(N);
    
    for (int i = 0; i < N; i++) {
      int n;
      scanf(" %d ", &n);
      series[i] = n;
    }
    
    int mx = -1000000000;
    for (int i = 0; i < N; i++) {
      int sum = 0;
      for (int j = i; j < N; j++) {
	sum += series[j];

	mx = max(mx, sum);
      }
    }
    printf("%d\n", mx);
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int main() {
    int n,ans;
    cin >> n;
    while(n!=0){
        int a[5001];
        for(int i=0;i<n;++i){
            cin >> a[i];
        }
        ans=a[1]+a[0];
        for(int i=0;i<n-2;++i){
            ans=max(ans,a[i+2]+a[i+1]);
        }
        cout << ans << endl;
        cin >> n;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;

int main(){
int n,Sum,Ans ;

while(1){

Ans=0 ;

cin >> n ;

if(n==0){
break ;
}

vector<int> vec(n+1,0) ;

for(int i=1;i<n+1;i++){
cin >> vec.at(i) ;
}

for(int j=0;j<n;j++){
vec.at(j+1)=vec.at(j)+vec.at(j+1) ;
}

for(int k=0;k<n+1;k++){
    for(int l=k+1;l<n+1;l++){
    Sum=vec.at(l)-vec.at(k);
    Ans=max(Sum,Ans) ;
    }
}
cout << Ans << endl ;

}
}

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

inline int max(int a, int b){
	return (a>b)? a : b ;
}

int main(){
	int n, max1, max2, a[5001];

	while( cin >> n , n ){
		for(int i=0 ; i<n ; i++){
			cin >> a[i] ;
		}
		max1 = a[0];

		for(int i=0 ; i<n ; i++){
			int sum = 0;
			for(int j=i ; j<n ; j++){
				sum += a[j];
				max1 = max( max1 , sum );
			}
		}
		cout << max1 << endl;
	}
}

C++: #define _USE_MATH_DEFINES
#include <iostream>
#include <sstream>
#include <cmath>
#include <algorithm>
#include <queue>
#include <stack>
#include <limits>

typedef long long ll;
using namespace std;


int sum(int i,int* bit){
	int s = 0;
	while(i > 0){
		s += bit[i];
		i -= i & -i;
	}
	return s;
}

void add(int i, int x,int* bit,int n){
	while(i <= n){
		bit[i] += x;
		i += i & -i;
	}	
}

int main()
{
	int T;
	while(~scanf("%d",&T)){
		if(T==0) break;
		int* bit = new int[T+1]();	
		int res=numeric_limits<int>::min();
		for(int t=1;t<=T;t++){
			int tmp;
			scanf("%d",&tmp);
			add(t,tmp,bit,T);
		}

		for(int a=0;a<=T;a++){
			for(int b=a+1;b<=T;b++){
				res=max(sum(b,bit) - sum(a,bit),res);
			}
			//cout << sum(a,bit) << endl;
		}
		
		printf("%d\n",res);
	}
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
  int n;
  while(cin >>n,n){
    vector<long int> a,b;
    for(int i=0,j; i<n; i++){
      cin >>j;
      a.push_back(j);
      if(i != 0) a[i]+=a[i-1];
    }
    b.push_back(0);
    for(int i=0; i<n; i++) b.push_back(min(b[i],a[i]));
    long int ans = a[0];
    for(int i=1; i<n; i++) ans = max(ans,a[i]-b[i]);
    cout <<ans<<endl;
  }
  return 0;
}

C++: #include<iostream>
#include<vector>

using namespace std;

int main(){

  int n;


  while(cin >> n){
    if(n == 0) break;
    vector<int> V;
    int status = 1;
    int in;
    int sum = 0;
    for(int i = 0; i < n; i++){
      cin >> in;
      if(i == 0){
	if(in < 0) status = -1;
	else status = 1;

      } else {
	if(in == 0) V.push_back(0);

	if(in < 0 && status == 1){
	  status = -1;
	  V.push_back(sum);
	  sum = 0;
	}else if(in > 0 && status == -1){
	  status = 1;
	  V.push_back(sum);
	  sum = 0;
	}
      }
      sum += in;
    }

    V.push_back(sum);

    int max = -700000000;
    
    for(int i = 0; i < V.size(); i++){
      sum = 0;
      for(int j = i; j < V.size(); j++){
	sum += V[j];
	if(max < sum) max = sum;
      }
    }
    
    cout << max << endl;
  }
  return 0;
}

C++: 
#include <iostream>
#include <queue>
#include <algorithm>

using namespace std;

int main() {
    while(true) {
        int N;
        cin >> N;
        if(!N) break;

        queue<int> q;
        int ans = -100000;
        int sump = 0, sumn = 0;
        int left = 0;
        while(N--) {
            int n;
            cin >> n;
            q.push(n);
            if(n >= 0) sump += n;
            else sumn += -n;
            while(!q.empty() && sump <= sumn) {
                int np = q.front();
                if(np >= 0) sump -= np;
                else sumn -= -np;
                q.pop();
            }
            ans = max(ans, sump-sumn);
        }
        cout << ans << endl;
    }
    return 0;
}

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

int main(void) {
    int num;
    while(cin >> num, num != 0) {
        int ary[num + 1];
        ary[0] = 0;
        for(int r = 1; r <= num; r++) {
            int input; cin >> input;
            ary[r] = ary[r - 1] + input;
        }
        int max = ary[1];
        for(int r = 1; r <= num; r++) {
            for(int c = 0; c <= r; c++) {
                int val = ary[r] - ary[c];
                if(val > max) max = val;
            }
        }
        
        cout << max << endl;
    }
    return(0);
}

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

int main(){
    int a[5000], n, i, j;
    while (cin >> n && 1 <= n && n <= 5000){
        int maximum = -100000, sum = 0;
        for(i = 0; i < n; i++){
            cin >> a[i];
         }
        for(i = 0; i < n; i++){
            for (j = i; j < n; j++){
                sum += a[j];
                maximum = max(maximum, sum);
            }
        }
        cout << maximum << endl;
    }
}