제출 #264796

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
264796		anubhavdhar	Building Bridges (CEOI17_building)	C++14	100 / 100	152 ms	9848 KiB

building

#include<bits/stdc++.h>

#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first 
#define ss second
#define vi vector<int>
#define vl vector<ll>
#define vii vector<pii>
#define vll vector<pll>
#define FOR(i,N) for(i=0;i<(N);++i)
#define FORe(i,N) for(i=1;i<=(N);++i)
#define FORr(i,a,b) for(i=(a);i<(b);++i)
#define FORrev(i,N) for(i=(N);i>=0;--i)
#define F0R(i,N) for(int i=0;i<(N);++i)
#define F0Re(i,N) for(int i=1;i<=(N);++i)
#define F0Rr(i,a,b) for(ll i=(a);i<(b);++i)
#define F0Rrev(i,N) for(int i=(N);i>=0;--i)
#define all(v) (v).begin(),(v).end()
#define dbgLine cerr<<" LINE : "<<__LINE__<<"\n"
#define ldd long double

using namespace std;

const int Alp = 26;
const int __PRECISION = 9;
const int inf = 1e9 + 8;

const ldd PI = acos(-1);
const ldd EPS = 1e-7;

const ll MOD = 1e9 + 7;
const ll MAXN = 1e5 + 5;
const ll ROOTN = 320;
const ll LOGN = 18;
const ll INF = 1e18 + 1022;

int N;
ll dp[MAXN], pre[MAXN], h[MAXN];

struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k < o.k; }
	bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) { x->p = inf; return false; }
		if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		auto l = *lower_bound(x);
		// cout<<l.k<<"x + "<<l.m<<" out of "<<size()<<"lines : ";
		return l.k * x + l.m;
	}
} box ;

signed main()
{

	/*
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	*/

	ll w;
	cin>>N;
	F0R(i, N)
		cin>>h[i];
	F0R(i, N)
		cin>>w, pre[i] = w + ((i == 0) ? 0 : pre[i-1]);

	dp[0] = 0;
	box.add(2*h[0], (- h[0]*h[0] - dp[0] + pre[0]));

	F0Re(i, N-1)
	{
		dp[i] = (h[i] * h[i] + pre[i-1]) - box.query(h[i]);
		box.add(2*h[i], (- h[i]*h[i] - dp[i] + pre[i]));
	}
	
	//F0R(i, N)
	//	cout<<"dp["<<i<<"] = "<<dp[i]<<'\n';
	cout<<dp[N-1]<<'\n';

	return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40