Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func max(x, y int) int {
	if x > y {
		return x
	} else {
		return y
	}
}

func main() {
	sum := make([]int, 5001)
	for {
		n := nextInt()
		if n == 0 {
			break
		}
		for i := 0; i < n; i++ {
			a := nextInt()
			sum[i+1] = sum[i]+a
		}
		ret := sum[1]
		for i := 0; i <= n; i++ {
			for j := i + 1; j <= n; j++ {
				ret = max(ret, sum[j]-sum[i])
			}
		}
		fmt.Println(ret)
	}
}

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

using namespace std;

#define FOR(a) for(int i = 0; i < a; i++)
#define FORR(a, b) for(int i = a; i < b; i++)

int main(void){
	int Max, Num = -1, In, N = 0;
	while (Num != 0){
		vector<int>	Dat;
		Max = -100000;
		cin >> Num;
		Dat.push_back(-100000);
		FOR(Num){
			cin >> In;
			Dat.push_back(In);
		}
		FORR(1, Num + 1){
			Dat[i] = max(Dat[i], Dat[i - 1] + Dat[i]);
			Max = max(Max, Dat[i]);
		}
		cout << Max << endl;
	}
	return 0;
}

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

#define INF -100000000

int main(){
  

  int dataSets;

  while(true){
    vector<int> a;
    cin >> dataSets;
    if(dataSets==0){break;}
    for(int i=0;i<dataSets;i++){
      int tmpa;
      cin >> tmpa;
      a.push_back(tmpa);

    }

    int tmax=INF;
    // i?????§????????§?????????????????????
    vector<int> tmpMax(dataSets + 1,0);
    tmpMax[0] = 0;
    for(int i=1;i<dataSets+1;i++){
      tmpMax[i] += tmpMax[i-1] + a[i-1];
    }

    for(int i=0;i<dataSets;i++){
      for(int j=i+1;j<dataSets+1;j++){
	tmax = max(tmax, tmpMax[j]-tmpMax[i]);
      }
    }
    
    // for(int i=0;i<dataSets+1;i++){
      // for(int j=i;j<dataSets;j++){
	// tmax = max(tmax, tmpMax[j+1] - tmpMax[i]);
      // }
    // }
    
    cout << tmax << endl;
    
  }

  return 0;

}

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

int main() {
	int n;
	while (true) {
		cin >> n;
		if (n == 0)break;
		int* nums = new int[n];
		for (int i = 0; i < n; i++) {
			cin >> nums[i];
		}
		int max = -100001; 
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n - i; j++) {
				int tmp = 0;
				for (int k = i; k <= j; k++) {
					tmp += nums[k];
				}
				if (max < tmp)max = tmp;
			}
		}
		cout << max << endl;
	}
}

C++: #include <cstdio>
#include <iostream>
#include <vector>
using namespace std;
typedef vector<int> vec;
#define INF (1<<20)

int main(){
	int n;
	while( cin >> n, n ){
		vec data(n);
		for( int i = 0; i < n; i++ ){
			cin >> data[i];
		}
		int ans = -INF;
		vector<vec> dp(n, vec(n));
		for( int i = 0; i < n; i++ ){
			for( int j = i; j < n; j++ ){
				if( i == 0 ){
					if( j == 0 ) dp[0][0] = data[0];
					else dp[0][j] = dp[0][j-1] + data[j];
					ans = max(ans, dp[i][j]);
				}else{
					//if( i <= j ){
						dp[i][j] = dp[i-1][j] - data[i-1];
						ans = max(ans, dp[i][j]);
					//}
				}
			}
		}
		/*for( int i = 0; i < n; i++ ){
			for( int j = 0; j < n; j++ ){
				printf("%4d", dp[i][j]);
			}
			cout << endl;
		}
		*/
		cout << ans << endl;
	}
}

C++: #include <iostream>
#include <iomanip>
#include <cassert>
#include <algorithm>
#include <functional>
#include <vector>
#include <string>
#include <cstring>
#include <stack>
#include <queue>
#include <map>
#include <bitset>
#include <sstream>
#include <istream>
#include <cmath>
#include <cstdio>

using namespace std;

#define vci vector<int>
#define vcs vector<string>
#define pb push_back
#define sz size()
#define mapci map<char, int>
#define mapsi map<string, int>
#define all(x) x.begin(), x.end()

#define for_(i, a, b) for (int i=(int)a; i<(int)b; i++)
#define for_d(i, a, b) for (int i=(int)a-1; i>=b; i--)
#define for_r(i, a, b, c) for (int i=(int)a; i<(int)b; i += c)
#define for_dr(i, a, b, c) for (int i=(int)a-1; i>=b; i -= c)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)

#define vcitr vector<int>::iterator
#define vcsitr vector<string>::iterator
#define mapcitr map<char, int>::iterator
#define mapsitr map<string, int>::iterator

typedef long long ll;

const int iINF = 2147483647;
const ll lINF = 9223372036854775807;

template <class T> inline void dbg(T t) { cout << t << endl; }

int a[5050];

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

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

using namespace std;

int main(void){
	int n, a[5000], res[5000], sum, i, j, ans;
	while(1){
		scanf("%d",&n);
		if(!n){
			break;
		}
		for(i = 0;i < n;i++){
			scanf("%d",&a[i]);
		}
		sum = 0;
		for(i = 0;i < n;i++){
			sum += a[i];
			res[i] = sum;
		}
		ans = 0;
		for(i = 0;i < n;i++){
			ans = max(ans,res[i]);
			for(j = 0;j < i;j++){
				ans = max(ans,res[i] - res[j]);
			}
		}
		printf("%d\n",ans);
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
int main(){
	for (;;){
		int a,goukei=0,max=-999999999,b;
		cin>>a;
		if (a==0)break;
		int data[a+1]={0};
		for (int A=1;A<=a;A++){
			cin>>data[A];
			if (max<data[A])max=data[A];
			goukei+=data[A];
			data[A]=goukei;
			if (max<data[A])max=data[A];
		}
		for (int A=3;A<a;A++){
			b=A-2;
			for (int B=b;B>0;B--){
				goukei=0;
				goukei=data[A]-data[B];
				if (goukei>max) max=goukei;
			}
		}
		cout<<max<<endl;
	}
	return 0;
}

C++: #include<cstdio>
#include<vector>
#include<deque>
using namespace std;
int main(){
    int n;
    for(;;){
        scanf("%d",&n);
        if(n==0) break;
        vector<int> numa(n);
        deque<int> suma;
        int ans=0;
        for(int i=0;i<n;i++){
            scanf("%d",&numa[i]);
        }
        
        bool isplus=numa[0]>=0;
        int nowsum=numa[0];
        for(int i=1;i<n;i++){
            if((numa[i]>=0) == isplus){
                nowsum+=numa[i];
            }else{
                isplus=numa[i]>=0;
                suma.push_back(nowsum);
                nowsum=numa[i];
            }
        }
        suma.push_back(nowsum);

        if(suma.front()<0){
            if(suma.size()==1){
                int m=0;
                for(int i=0;i<n;i++){
                    if(m==0 || m<numa[i]) m=numa[i];
                }
                ans=m;
            }
            suma.pop_front();
        }else if(suma.size()==1){
            for(int i=0;i<n;i++){
                ans+=numa[i];
            }
        }

        while(!suma.empty()){
            if(suma.size()>=3){
                nowsum=suma.front();
                suma.pop_front();
                while(suma.size()>=2 && suma[0]+suma[1]>0){
                    nowsum+=suma[0]+suma[1];
                    suma.pop_front();
                    suma.pop_front();
                }
                if(suma.size()>=2) suma.pop_front();
                if(ans<nowsum) ans=nowsum;
            }else if(suma.size()==2){
                if(ans<suma[0]) ans=suma[0];
                suma.pop_front();
                suma.pop_front();
            }else if(suma.size()==1){
                if(ans<suma[0]) ans=suma[0];
                suma.pop_front();
            }
        }
        printf("%d\n",ans);
    }
}