Submission #31088

#	Time	Username	Problem	Language	Result	Execution time	Memory
31088		nibnalin	Hacker (BOI15_hac)	C++14	100 / 100	693 ms	17676 KiB

hac

#include <iostream>
#include <cstdio>
#include <vector>
#include <set>
using namespace std;

const int maxn = int(5e5)+5, inf = int(1e9)+5;

int n, A[maxn], v[maxn];

inline int mod(int x) { return ((x%n)+n)%n; }

int main(void)
{
	scanf("%d", &n);
	for(int i = 0;i < n;i++) scanf("%d", &A[i]);
	int sz = n/2+n%2;
	for(int i = 0;i < sz;i++) v[0] += A[i];
	
	for(int i = 1;i < n;i++)
	{
		v[i] = v[i-1]+A[mod(i+sz-1)]-A[i-1];
	}
	
	set<pair<int, int>> S;

	for(int i = 0;i < sz;i++) S.insert({v[mod(0-i)], mod(0-i)});

	int res = S.begin()->first;
	for(int i = 0;i < n;i++)
	{
		S.erase({v[mod(i-sz)], mod(i-sz)}), S.insert({v[i], i});
		res = max(res, S.begin()->first);
	}
	printf("%d\n", res);
}

Compilation message (stderr)

hac.cpp: In function 'int main()':
hac.cpp:15:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
hac.cpp:16:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 0;i < n;i++) scanf("%d", &A[i]);
                                             ^

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