Submission #568383

#	Time	Username	Problem	Language	Result	Execution time	Memory
568383		CSQ31	Boxes with souvenirs (IOI15_boxes)	C++17	10 / 100	1 ms	340 KiB

boxes

#include "boxes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;

ll delivery(int n, int k, int L, int p[]) {
	vector<ll>pref(n,0),suff(n,0);
	vector<vector<int>>c(k);
	for(int i=0;i<n;i++)c[i%k].push_back(i);
	for(int i=0;i<k;i++){
		int s = c[i].size();
		ll sum = 0;
		for(int j=0;j<s;j++){
			sum+=p[c[i][j]];
			if(j>=k)sum-=p[c[i][j-k]];
			pref[c[i][j]] = 2*sum;
			
		}
		sum = 0;
		for(int j=s-1;j>=0;j--){
			sum+=L-p[c[i][j]];
			if(j+k<s)sum-=p[c[i][j+k]];
			suff[c[i][j]] = 2*sum;
		}
	}
	ll ans = 1e18;
	ans = min(ans,suff[0]);
	ans = min(ans,pref[n-1]);
	for(int i=0;i+1<n;i++)ans = min(ans,pref[i] + suff[i+1]);
	for(int i=k-1;i<n;i++){
		ll cost = L;
		if(i-k>=0)cost+=pref[i-k];
		if(i+1<n)cost+=suff[i+1];
		ans = min(ans,cost);
	}
	return ans;
}

Compilation message (stderr)

boxes.cpp: In function 'll delivery(int, int, int, int*)':
boxes.cpp:11:20: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   11 |   int s = c[i].size();
      |           ~~~~~~~~~^~

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