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Submission #264806

# Submission time Handle Problem Language Result Execution time Memory
264806 2020-08-14T10:00:24 Z anubhavdhar Building Bridges (CEOI17_building) C++14
100 / 100
 141 ms 9208 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("min");

	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 0 ms 384 KB Output is correct
2 Correct 1 ms 288 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 130 ms 2712 KB Output is correct
2 Correct 130 ms 3064 KB Output is correct
3 Correct 129 ms 3064 KB Output is correct
4 Correct 129 ms 3084 KB Output is correct
5 Correct 116 ms 4344 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 1 ms 288 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 130 ms 2712 KB Output is correct
7 Correct 130 ms 3064 KB Output is correct
8 Correct 129 ms 3064 KB Output is correct
9 Correct 129 ms 3084 KB Output is correct
10 Correct 116 ms 4344 KB Output is correct
11 Correct 139 ms 2936 KB Output is correct
12 Correct 130 ms 3064 KB Output is correct
13 Correct 126 ms 2936 KB Output is correct
14 Correct 141 ms 2936 KB Output is correct
15 Correct 137 ms 9208 KB Output is correct
16 Correct 114 ms 4088 KB Output is correct
17 Correct 113 ms 2936 KB Output is correct
18 Correct 113 ms 2936 KB Output is correct