Submission #393230

#	Time	Username	Problem	Language	Result	Execution time	Memory
393230		bigg	Boxes with souvenirs (IOI15_boxes)	C++14	100 / 100	522 ms	196120 KiB

boxes

#include "boxes.h"
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 1e7 + 10;
ll pref[MAXN], suf[MAXN];
const ll INF = 1e18 + 10;
long long delivery(int N, int K, int L, int p[]) {
	
	for(int i = 0; i < N; i++){
		pref[i] = p[i];
		if(!(i < K)) pref[i] += pref[i-K];
	} 
	for(int i = N - 1; i >= 0; i--){
		suf[i] = L-p[i];
		if(!(K+i >= N)) {
			suf[i] += suf[i+K];
		}
	}
	// vai e volta por um lado
	ll ans = min(2*suf[0], 2*pref[N-1]);
	if(K >= N) ans = min(ans, (ll) L);
	for(int i = 0; i < N-1; i++) ans = min(ans, 2*suf[i+1] + 2*pref[i]);
	// achar  volta
	if(K < N){
		for(int i = 1; i+K < N; i++ ){
			ans = min(ans, L + 2*pref[i-1] + 2*suf[i+K]);
		}
		ans = min(ans, L + 2*pref[N-K-1]);
		ans = min(ans, L + 2*suf[K]); // dou a volta, e pego o resto com uma ida do outro lado
	}
	
	return ans;
    //return 0;

}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 30 / 30