제출 #158449

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
158449		dennisstar	Aliens (IOI16_aliens)	C++11	4 / 100	7 ms	5112 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pl;

vector<pl> pii, ar; 
vector<pl> lines[100010]; int fr[100010], bk[100010];
vector<ll> Dp[100010];

ld cr(pl a, pl b) {
	return (ld)(a.se-b.se)/(b.fi-a.fi);
}

void insert(int lev, ll p, ll q)
{
	lines[lev][bk[lev]]={p,q};
	while (bk[lev]>1 && cr(lines[lev][bk[lev]-1], lines[lev][bk[lev]-2])>cr(lines[lev][bk[lev]-1], lines[lev][bk[lev]])) {
		lines[lev][bk[lev]-1]=lines[lev][bk[lev]]; bk[lev]--;
	}
	bk[lev]++;
}

ll f(int lev, ll x) {
	while (fr[lev]+1<bk[lev]&&cr(lines[lev][fr[lev]], lines[lev][fr[lev]+1])<=(ld)x) fr[lev]++;
	return x*x+lines[lev][fr[lev]].fi*x+lines[lev][fr[lev]].se;
}

ll take_photos(int n, int m, int k, vector<int> r, vector<int> c) {
	int i, j;
	for (i=0; i<=k; i++) {lines[i].resize(n); Dp[i].resize(n);}
	for (i=0; i<n; i++) if (r[i]<c[i]) swap(r[i], c[i]);
	for (i=0; i<n; i++) pii.push_back({(ll)r[i],(ll)c[i]});
	sort(pii.begin(), pii.end());
	for (i=0; i<n; i++) {
		while (ar.size()&&ar.back().se>pii[i].se) ar.pop_back();
		ar.push_back(pii[i]);
	}
	insert(0, -2*(ar[0].se-1), (ar[0].se-1)*(ar[0].se-1));
	for (i=0; i<ar.size(); i++) {
		for (j=min(i+1,k); j>=1; j--) {
			Dp[j][i]=f(j-1, ar[i].fi);
			if (i==n-1) continue;
			if (ar[i].fi<ar[i+1].se) insert(j, -2*(ar[i+1].se-1), Dp[j][i]+(ar[i+1].se-1)*(ar[i+1].se-1));
			else insert(j, -2*(ar[i+1].se-1), Dp[j][i]+(ar[i+1].se-1)*(ar[i+1].se-1)-(ar[i].fi-ar[i+1].se+1)*(ar[i].fi-ar[i+1].se+1));
		}
	}
	ll ret=(1ll<<60);
	for (i=1; i<=min((int)ar.size(), k); i++) ret=min(ret, Dp[i][ar.size()-1]);
	return ret;
}

컴파일 시 표준 에러 (stderr) 메시지

aliens.cpp: In function 'll take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:43:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0; i<ar.size(); i++) {
            ~^~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40