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Submission #264803

# Submission time Handle Problem Language Result Execution time Memory
264803 2020-08-14T09:58:55 Z anubhavdhar Building Bridges (CEOI17_building) C++14
100 / 100
 144 ms 9848 KB 
#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 //mx + c
{
	mutable ll m, c, p;
	bool operator < (const line& o) const {return m < o.m;}
	bool operator < (ll x) const {return p < x;}
};

struct CHT_black_box : multiset<line, less<>>
{
	int mode;
	void set_mode(string S) {mode = (S[1] == 'i' || S[1] == 'I') ? -1 : 1;}
	ll div(ll a, ll b) {return a/b - ((a^b) < 0 && a%b);}
	bool isect(iterator x, iterator y)
	{
		if(y == end()){x->p = INF; return false;}
		if(x->m == y->m)	x->p = (x->c > y->c) ? INF : -INF;
		else	x->p = div((y->c - x->c),(x->m - y->m));
		return (x->p >= y->p);
	}
	void add(ll slope, ll intercept)
	{
		auto z = insert({mode * slope, mode * intercept, 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);
		return mode * (l.m * x + l.c);
	}
}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]);

	box.set_mode("maximum");

	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
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 132 ms 3704 KB Output is correct
2 Correct 130 ms 3704 KB Output is correct
3 Correct 132 ms 3704 KB Output is correct
4 Correct 123 ms 3568 KB Output is correct
5 Correct 115 ms 4728 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 132 ms 3704 KB Output is correct
7 Correct 130 ms 3704 KB Output is correct
8 Correct 132 ms 3704 KB Output is correct
9 Correct 123 ms 3568 KB Output is correct
10 Correct 115 ms 4728 KB Output is correct
11 Correct 142 ms 3832 KB Output is correct
12 Correct 133 ms 3836 KB Output is correct
13 Correct 140 ms 3832 KB Output is correct
14 Correct 144 ms 3832 KB Output is correct
15 Correct 130 ms 9848 KB Output is correct
16 Correct 115 ms 4728 KB Output is correct
17 Correct 113 ms 3704 KB Output is correct
18 Correct 115 ms 3792 KB Output is correct