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<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<functional>
using namespace std;
int main(){
	int n;
	while(cin>>n,n){
		int sum=0,a[5001],ans=0;
		vector<int>anss(0);
		for(int i=0;i<n;i++)cin>>a[i];
		for(int i=0;i<n;i++){
			sum=0;
			for(int j=i;j<n;j++){
				sum+=a[j];
				ans=max(sum,ans);
				//anss.push_back(sum);
			}
		}
		cout<<ans<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<vector>
#include<cmath>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb(in,tmp) in.push_back(tmp)
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
using namespace std;
int main(){
  int n;
  vector<int>in(5000);
  while(cin>>n,n){
    rep(i,n)cin>>in[i];
    int max=0;
    rep(i,n){
      int sum=0;
      loop(j,i,n){
	sum+=in[j];
	if(max<sum)max=sum;
      }
    }
    cout<<max<<endl;
  }


}

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

using std::cin;

int main()
{

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

        std::vector<int> line(n);
        for (auto i = 0; i < n; i++) {
            int in;
            cin >> in;
            line.at(i) = in;
        }

        int max = -100000;
        for (auto i = 0; i < n; i++) {
            int sum_ij;
            int max_i;
            max_i = sum_ij = line.at(i);
            for (auto j = i + 1; j < n; j++) {
                sum_ij += line.at(j);
                if (sum_ij > max_i) {
                    max_i = sum_ij;
                }
            }
            if (max_i > max) {
                max = max_i;
            }
        }

        std::cout << max << std::endl;
    }

    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 sum[5000];//??????????????¨????????????.
int main(){
	int N;
	int ans = 0;
	while(cin>>N&&N){
		int index=0;
		ans = INT_MIN;//????????§??????????????¨????????????.
		FOR(i,0,N){
			cin>>sum[i];
			sum[i] += sum[i-1];
		}
		FOR(i,0,N){
			FOR(j,i,N){
				ans = max(ans,sum[j]-sum[i-1]);
			}
		}
		cout<< ans <<endl;
	}
}

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

int main() {
	int n;

	while (cin >> n) {
		if (n == 0) break;
		vector<int> array(n);
		for (int i = 0; i < n; i++) {
			cin >> array.at(i);
		}

		long max = array.at(0);
		for (int j = 0; j < n; j++) {
			long total = 0;
			for (int k = 0; k < n - j; k++) {
				total += array.at(j + k);
				if (total > max) max = total;
			}
		}

		cout << max << endl;
	}
	return 0;
}

C++: /**
 * http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=0022&lang=jp
 */
#include <stdio.h>

int getsign(int d){
	return d >= 0 ? 1 : -1;
}

int seqsum(int n){
	int a[5000];
	int b[5000];
	int c = 0;
	int s = 0;

	scanf("%d", a);
	b[0] = a[0];
	s = getsign(a[0]);

	for(int i=1; i<n; ++i){
		scanf("%d", a+i);
		if(s == getsign(a[i])){
			b[c] += a[i];
		}else{
			b[++c] = a[i];
			s = getsign(a[i]);
		}
	}

	int m = b[0];
	int sum = m;
	if(c == 0){
		if(m >= 0){ return m; }
		m = a[0];
		for(int i=1; i<n; ++i){
			if(m < a[i]){
				m = a[i];
			}
		}
		return m;
	}
	for(int i=1; i<=c; ++i){
		if(m < sum + b[i]){
			sum += b[i];
			m = sum;
		}else if(m < b[i]){
			sum = m = b[i];
		}else{
			sum += b[i];
		}
	}

	return m;
}

int main(void){
	int n = 0;
	while(true){
		scanf("%d", &n);
		if(n == 0){ break;}
		printf("%d\n", seqsum(n));
	}
	return 0;
}

C++: #include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
using namespace std;

typedef long long ll;
typedef pair<int, int> P;

#define all(c) (c).begin(), (c).end()
#define pb push_back
#define mp make_pair
#define EXIST(v,i) (find(all(v), i) != (v).end())
#define ERASE(v,i) (v).erase(remove(all(v), i), (v).end())
#define INDEX(v,i) (find(all(v), i) - (v).begin())
#define rep(i,n) for(int i = 0; i < (int)n; ++i)
#define debug(x) cerr << #x << " = " << (x) << endl;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

const int INF = 100000000;
const double PI = 3.14159265358979323846;
const double EPS = 1e-10;

int main() {
	for(int n; cin >> n && n;) {
		vector<int> arr(n);
		vector<int> cur(n);
		rep(i,n) cin >> arr[i];
		if(arr[0] > 0) cur[0] = arr[0];
		for(int i = 1; i < n; i++)
			cur[i] = max(arr[i], cur[i - 1] + arr[i]);
		cout << *max_element(all(cur)) << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,l,n) for(int i=l;i<n;i++)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
using namespace std;

int main(){
	int n;
	while(1){
		cin>>n;
		if(n==0) break;
		vector<int> a(n);
		rep(i,0,n) cin>>a[i];
		int MAX=0;
		rep(i,0,n){
			int sum=0;
			rep(j,i,n){
				sum+=a[j];
				MAX=max(MAX,sum);
			}
		}
		o(MAX);
	}
}

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

int main(){
        int n,a[5010];
        while(cin>>n && n){
                for(int i=0; i<n; i++) cin >> a[i];
                long max = 0;
                for(int k = 0; k < n; k++){
                        long sum = 0;
                        for(int i=0; i<n-k; i++){
                                sum += a[i];
                                max = (max>sum)? max:sum;
                        }
                        for(int i=0; i<=k; i++){
                                sum += (a[n-k+i]-a[i]);
                                max = (max>sum)? max:sum;
                        }
                }
                cout << max << endl;
        }

}