Problem:
Maximum Sum Sequence

Given a sequence of numbers a1, a2, a3, ..., an, find the maximum sum of a contiguous subsequence of those numbers. Note that, a subsequence of one element is also a contiquous subsequence.

Input

The input consists of multiple datasets. Each data set consists of:

n
a1
a2
.
.
an

You can assume that 1 ≤ n ≤ 5000 and -100000 ≤ ai ≤ 100000.

The input end with a line consisting of a single 0.

Output

For each dataset, print the maximum sum in a line.

Sample Input

7
-5
-1
6
4
9
-6
-7
13
1
2
3
2
-2
-1
1
2
3
2
1
-2
1
3
1000
-200
201
0

Output for the Sample Input

19
14
1001

Solution in JAVA (judge verdict: Accepted)

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        String line;
        while (!(line = br.readLine()).equals("0")) {
            int n = Integer.parseInt(line);

            // 累積和配列を用いたアルゴリズムO(n^2)
            int[] s = new int[n + 1];
            for (int i = 1; i <= n; i++) {
                s[i] = Integer.parseInt(br.readLine()) + s[i - 1];
            }
            
            int sum = Integer.MIN_VALUE;
            
            for (int l = 0; l <= n-1; l++) {
                for (int r = l+1; r <= n; r++) {
                    sum = Math.max(sum, s[r] - s[l]);
                }
            }

            System.out.println(sum);
        }

    }
}