Marvolo Gaunt's Ring CodeForces - 855B

Professor Dumbledore is helping Harry destroy the Horcruxes. He went to Gaunt Shack as he suspected a Horcrux to be present there. He saw Marvolo Gaunt's Ring and identified it as a Horcrux. Although he destroyed it, he is still affected by its curse. Professor Snape is helping Dumbledore remove the curse. For this, he wants to give Dumbledore exactly x drops of the potion he made.

Value of x is calculated as maximum of p·ai + q·aj + r·ak for given p, q, r and array a1, a2, ... an such that 1 ≤ i ≤ j ≤ k ≤ n. Help Snape find the value of x. Do note that the value of x may be negative.

Input

First line of input contains 4 integers n, p, q, r ( - 109 ≤ p, q, r ≤ 109, 1 ≤ n ≤ 105).

Next line of input contains n space separated integers a1, a2, ... an ( - 109 ≤ ai ≤ 109).

Output

Output a single integer the maximum value of p·ai + q·aj + r·ak that can be obtained provided 1 ≤ i ≤ j ≤ k ≤ n.

Example

Input
5 1 2 3
1 2 3 4 5
Output
30
Input
5 1 2 -3
-1 -2 -3 -4 -5
Output
12

Note

In the first sample case, we can take i = j = k = 5, thus making the answer as 1·5 + 2·5 + 3·5 = 30.

In second sample case, selecting i = j = 1 and k = 5 gives the answer 12.

题解:注意顺序是一定的,i<=j<=k,所以可以枚举中间值j,然后用两个数组分别存第一项的前缀最大值,第三项的后缀最大值,最后加起来遍历一遍就行了。

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 
 5 const int maxn=1e5+5;
 6 
 7 ll n,p,q,r;
 8 ll a[maxn],b[maxn],c[maxn];
 9 
10 int main()
11 {   cin>>n>>p>>q>>r;
12     ll temp;
13     for(int i=1;i<=n;i++){
14         cin>>temp;
15         a[i]=p*temp;
16         b[i]=q*temp;
17         c[i]=r*temp;
18     }    
19     temp=a[1];
20     for(int i=1;i<=n;i++){
21         temp=max(temp,a[i]);
22         a[i]=temp;
23     }
24     temp=c[n];
25     for(int i=n;i>=1;i--){
26         temp=max(temp,c[i]);
27         c[i]=temp;
28     }
29     temp=a[1]+b[1]+c[1];
30     for(int i=1;i<=n;i++) temp=max(temp,a[i]+b[i]+c[i]);
31     cout<<temp<<endl;
32 }

 

posted @ 2017-10-27 22:13  天之道,利而不害  阅读(316)  评论(0编辑  收藏  举报