Submission #909403

#	Time	Username	Problem	Language	Result	Execution time	Memory
909403		shoryu386	Hacker (BOI15_hac)	C++17	100 / 100	435 ms	46140 KiB

hac

#include <bits/stdc++.h>
using namespace std;
#define MAX 200007
#define int long long
main(){
	int n; cin >> n;
	
	int count = (n+1)/2;
	
	int arr[2*n];
	for (int x = 0; x < n; x++) cin >> arr[x];
	for (int x = 0; x < n; x++) arr[n + x] = arr[x];
	
	int psum[2*n];
	psum[0] = arr[0];
	for (int x = 1; x < 2*n; x++) psum[x] = psum[x-1] + arr[x];
	
	#define rq(a, b) ((a==0) ? psum[b] : psum[b] - psum[a-1])
	
	int hmm[2*n]; memset(hmm, 63, sizeof(hmm));
	int sums[2*n];
	for (int x = 0; x < 2*n; x++){
		int sum = rq(x, x+count-1);
		sums[x] = sum;
	}
	
	multiset<int> ms;
	for (int x = 0; x < count; x++){
		ms.insert(sums[x]);
	}
	
	memset(hmm, -63, sizeof(hmm));
	hmm[0] = *ms.begin();
	
	for (int x = 1; x < n; x++){
		ms.insert(sums[count+x-1]);
		ms.erase(ms.find(sums[x-1]));
		
		hmm[x] = *ms.begin();
	}
	
	int ans = INT_MIN;
	for (int x = 0; x < n; x++){
		ans = max(ans, hmm[x]);
	}
	cout << ans;
}

Compilation message (stderr)

hac.cpp:5:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    5 | main(){
      | ^~~~

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