And the largest sub-segment (Los Valley P1115)

Title Description

Given a sequence, wherein the selected period of continuous and non-empty and that this maximum.

Input Format

The first line is a positive integer NN N, denotes the length of the sequence.

The second line contains NN N absolute value is not greater than 1.00001 billion . 1 0 0 0 integer of 0 AiA_i A I , this sequence is described column.

Output Format

An integer, the largest sub-segment and how much. The minimum length of the sub segment is . 11 1

Sample input and output

Input # 1

7 2 -4 3 -1 2 -4 3

Output # 1

4

Description / Tips

[Sample Description]

2, -4,3, -1,2, -4,32, -4,3, -1,2, -4,3 2 , - . 4 , 3 , - . 1 , 2 , - . 4 , 3, the maximum the sub-segments and 4, the sub-segment 3, -1,23, 1,2 3 , - . 1 , 2.

[Agreed] with the scale data

For 40% 40 \% . 4 0 % of the data, there N≤2000N 2000 ≤ N ≤ 2 0 0 0.

For 100% 100 \% . 1 0 0 % of the data, there N≤200000N 200000 ≤ N ≤ 2 0 0 0 0 0.

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It is still difficult for the popularity - and thought acridine prefix -

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 int n,k,ans,minn,maxn=-9999;
 4 int a[200010],b[200010];
 5 int main()
 6 {
 7     cin>>n;
 8     for(int i=1;i<=n;i++)
 9     {
10         cin>>a[i];
11         a[i]+=a[i-1];//前缀和
12     }
13     B [ . 1 ] = A [ . 1 ]; Minn = min ( 0 , A [ . 1 ]); // A [. 1] may be negative 
14      for ( int I = 2 ; I <= n-; I ++ )
 15      {
 16          B [I] = a [I] -minn; // Minn subtracting the minimum required prefix 
. 17          Minn = min (Minn, a [I]); // remember to update 
18 is      }
 . 19      for ( int I = . 1 ; I < n-=; i ++ )
 20 is          MAXN = max (MAXN, B [i]); // B [i] for the ending of the maximum i and sub-segment 
21 is      COUT << MAXN;
22     return 0;
23 }