Submission #173090

#	Time	Username	Problem	Language	Result	Execution time	Memory
173090		dvdg6566	Building Bridges (CEOI17_building)	C++14	0 / 100	125 ms	5752 KiB

building

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<ld> vi;
typedef pair<ld,ld> pi;
typedef vector<pi> vpi;
typedef long double ld;
#define pb emplace_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define All(x) x.begin(), x.end()
#define SZ(x) (ll)x.size()
#define f first
#define s second

typedef ll ftype;
typedef complex<ftype> poll;
#define x real
#define y imag

ftype dot (poll a, poll b){
	return (conj(a)*b).x();
}

ftype f(poll a, ftype x){
	return dot(a, {x,1});
}

const ll MAXN = 2e5;
poll line [4*MAXN];

void add_line(poll nw, ll v=1, ll l=0, ll r=MAXN){
	// if (l==0 && r == MAXN){
	// 	cout<<nw.x<<' '<<nw.y<<'\n';
	// }
	ll m=(l+r)/2;
	bool lef = f(nw, l) < f(line[v], l);
	bool mid = f(nw, m) < f(line[v], m);
	if (mid){
		swap(line[v], nw);
	}
	if (r-l == 1)return;
	if (lef != mid)add_line(nw,2*v,l,m);
	else add_line(nw, 2*v+1, m, r);
}

ll get(ll x, ll v=1, ll l=0, ll r=MAXN){
	ll m=(l+r)/2;
	if (r-l == 1)return f(line[v], x);
	if (x<m)return min(f(line[v], x), get(x, 2*v, l, m));
	else return min(f(line[v], x), get(x,2*v+1,m,r));
}

ll N,H[MAXN], E[MAXN];
ll W;
ll dp[MAXN];

int main(){
	cin>>N;
	for (ll i=1;i<=N;++i)cin>>H[i];
	for (ll i=1;i<=N;++i)cin>>E[i], W += E[i];
	dp[1] = -E[1];
	add_line({-2*H[1], dp[1] + H[1] * H[1]});
	// cout<<dp[1] + H[1] * H[1]<<' '<<-2*H[1]<<'\n';
	// return 0;
	for (ll i=2;i<=N;++i){
		dp[i] = H[i] * H[i] - E[i] + get(H[i]);
		add_line({-2*H[i], H[i] * H[i] + dp[i]});
		// cout<<H[i] * H[i] - E[i]<<' '<<dp[i]<<'\n';
		// return 0;
	}
	cout<<dp[N]+W;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40