Submission #668842

#	Time	Username	Problem	Language	Result	Execution time	Memory
668842		Astrayt	Boxes with souvenirs (IOI15_boxes)	C++17	10 / 100	1 ms	212 KiB

boxes

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ll long long
#define pii pair<int,int>
#define All(x) x.begin(), x.end()

ll delivery(int N, int K, int L, int pos[]){
	ll ans = 0;
	vector<int> lp, rp;
	int in_mid = 0;
	for(int i = 0; i < N; ++i){
		if(pos[i] == L / 2 && L % 2 == 0) in_mid++;
		else if(pos[i] != 0 && pos[i] <= L / 2) lp.pb(pos[i]);
		else if(pos[i] > L / 2) rp.pb(pos[i]);
	}
	reverse(All(rp));
	while(in_mid){
		in_mid--;
		int k = min((int)lp.size() + (int)rp.size() + in_mid, K - 1);
		for(; k; k--){
			int l = (lp.size() ? lp.back() : -1), r = (rp.size() ? rp.back() : L + 1);
			if(l == -1 && r == L + 1){
				in_mid--;
				continue;
			}
			if(l < (L - r)) rp.pop_back();
			else if(l > (L - r)) lp.pop_back();
			else{
				lp.pop_back(), rp.pop_back();
				int nl = (lp.size() ? lp.back() : -1), nr = (rp.size() ? rp.back() : L + 1);
				if(nl < (L - nr)) lp.pb(l);
				else rp.pb(r);
			}
		}
		ans += 1ll * L;
	}
	int cur = lp.size() + rp.size();
	for(int i = cur; i > 0; i -= K){
		int k = min(K, i);
		ll ml = 0, mr = 0;
		for(; k; k--){
			int l, r;
			l = (lp.size() ? lp.back() : -1), r = (rp.size() ? rp.back() : L + 1);
			if(mr && r != L + 1) rp.pop_back(), mr = max(mr, 1ll * (L - r));
			else if(ml && l != -1) lp.pop_back(), ml = max(ml, 1ll * l);
			else {
				if(ml && l == -1 && 2ll * ml + 2ll * (L - r) < L) break;
				if(mr && r == L + 1 && 2ll * mr + 2ll * l < L) break;
				if(r == L + 1) lp.pop_back(), ml = max(ml, 1ll * l);
				else rp.pop_back(), mr = max(mr, 1ll * (L - r));
			}
		}
		ans += min(2ll * (ml + mr), 1ll * L);
	}
	return ans;
}

Compilation message (stderr)

boxes.cpp: In function 'long long int delivery(int, int, int, int*)':
boxes.cpp:38:22: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   38 |  int cur = lp.size() + rp.size();
      |            ~~~~~~~~~~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30