Submission #505985

#	Time	Username	Problem	Language	Result	Execution time	Memory
505985		sidon	Candies (JOI18_candies)	C++17	0 / 100	2 ms	464 KiB

candies

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
 
const int Z = 200'002;
const ll oo = 1e18;
 
/*
Take maximum value (say A[i]) for K = 1, then we have that we either
take A[i] or both A[i-1] and A[i+1]. So add a virtual element weighing
A[i-1] - A[i] + A[i+1] replacing these three elements. Now solve
inductively for (K - 1).
*/
 
int N, L[Z], R[Z];
ll A[Z], sum;
 
int main() {
	ios::sync_with_stdio(0), cin.tie(0);
	cin >> N;
 
	priority_queue<array<ll, 2>> pq;
 
	for(int i = 1; i <= N; i++) {
		cin >> A[i];
		L[i] = i - 1;
		R[i] = i + 1;
		pq.push({A[i], i});
	}
 
	A[0] = A[N+1] = oo;
	R[N+1] = N+1;
	R[0] = 1, L[N+1] = N;
 
	for(int k = 1; k<=(N+1)/2; k++) {
		while(A[pq.top()[1]] == oo) pq.pop();
		auto [v, i] = pq.top(); pq.pop();
 		bool bad = !L[i] || R[i] > N;
		cout << (sum += v) << '\n';
		if(A[L[i]] != oo) v -= A[L[i]], A[L[i]] = oo;
		if(A[R[i]] != oo) v -= A[R[i]], A[R[i]] = oo;
		pq.push({A[i] = -v, i});
		R[L[i] = L[L[i]]] = i;
		L[R[i] = R[R[i]]] = i;
		if(bad) A[i] = oo;
	}
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 92