Submission #42647

#	Time	Username	Problem	Language	Result	Execution time	Memory
42647		XmtosX	Hacker (BOI15_hac)	C++14	100 / 100	575 ms	35124 KiB

hac

#include <bits/stdc++.h>
using namespace std;
int n,v[500005],here[500005],ans;
set <pair<int,int> > s;
int main()
{
    scanf("%d",&n);
    for (int i=0;i<n;i++)
        scanf("%d",&v[i]);
    int k= (n/2)+(n%2),cur=0;
    for (int i=0;i<k;i++)
        cur+=v[i];
    for (int i=0;i<n;i++)
    {
        int j= (i+k)%n;
        cur-=v[i];
        cur+=v[j];
        here[(i+1)%n]=cur;
    }
    for (int i=0;i<k;i++)
        s.insert({here[i],i});
    for (int i=0;i<n;i++)
    {
        int j= (i+k)%n;
        s.erase({here[i],i});
        s.insert({here[j],j});
        ans=max(ans,s.begin()->first);
    }
    cout <<ans;
    return 0;
}

Compilation message (stderr)

hac.cpp: In function 'int main()':
hac.cpp:7:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
                   ^
hac.cpp:9:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&v[i]);
                          ^

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 40 / 40