Submission #896197

#	Time	Username	Problem	Language	Result	Execution time	Memory
896197		thunopro	Building Bridges (CEOI17_building)	C++14	100 / 100	59 ms	130100 KiB

building

#include<bits/stdc++.h>
using namespace std ; 
#define ll long long 
#define maxn 200009 
#define fi first 
#define se second 
#define pb push_back 
#define left id<<1 
#define right id<<1|1 
#define re exit(0); 
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()+1  
 
const int mod = 1e9+7 ; 
const int INF = 1e9 ; 
const int LOG = 18 ; 
 
typedef vector<int> vi ; 
typedef pair<int,int> pii ; 
typedef vector<ll> vl ; 
typedef vector<pii> vii ; 
 
void add ( int &a , int b ) 
{
	a += b ;
	if ( a < 0 ) a += mod ; 
	if ( a >= mod ) a -= mod ; 
}
 
template < typename T > void chkmin ( T &a , T b ) { if ( a > b ) a = b ; } 
template < typename T > void chkmax ( T &a , T b ) { if ( a < b ) a = b ; } 
 
void rf () 
{
	freopen ("bai1.inp","r",stdin) ; 
//	freopen ("bai1.out","w",stdout) ; 
}
 
int _pow ( int a , int n ) 
{
	if ( n == 0 ) return 1 ; 
	int res = _pow (a,n/2) ; 
	if ( n % 2 ) return 1ll*res*res%mod*a%mod ; 
	else return 1ll*res*res%mod ; 
}
 
int n ; 
ll dp [maxn] ; 
int h [maxn] , w [maxn] ; 
ll sw [maxn] ; 
 
ll sqr ( int x ) 
{
	return 1ll*x*x ; 
}
 
struct line {
	int a ; ll b ; 
	line () { a = 0 , b = 1e18 ; } ; 
	line ( int _a , ll _b ) 
	{
		a = _a , b = _b ; 
	}
	ll eval ( int x ) 
	{
		return 1ll*x*a+b ; 
	} 
};
 
const int N = 2e6 ; 
const int maxN = 2e6+2 ; 
struct lichao {
	line T [maxN*4] ; 
	void update ( int id , int l , int r , line L ) 
	{
		if ( l == r ) 
		{
			if ( T[id].eval(l) > L.eval(l) ) T [id] = L ; 
			return ; 
		}
		int mid = (l+r)/2 ; 
		if ( T[id].a > L.a ) swap (T[id],L) ; 
		if ( T[id].eval(mid)>L.eval(mid)) swap (T[id],L) , update (right,mid+1,r,L) ; 
		else update (left,l,mid,L) ; 
	}
	ll get ( int id , int l , int r , int x ) 
	{
		if ( l == r ) return T [id].eval(x) ; 
		int mid = (l+r)/2 ; 
		if ( x <= mid ) return min(T[id].eval(x),get(left,l,mid,x)) ;
		else return min (T[id].eval(x),get(right,mid+1,r,x)) ; 
	}	
	void update ( line L )
	{
		update (1,1,N,L) ; 
	}
	ll get ( int x ) 
	{
		return get (1,1,N,x) ; 
	}
}T;
void add_lichao ( int i ) 
{
	line L = {-h[i],dp[i]+sqr(h[i])-sw[i]} ; 
	T.update (L) ; 
}
int main () 
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);cout.tie(0) ; 
//	rf () ; 
	cin >> n ; 
	for ( int i = 1 ; i <= n ; i ++ ) cin >> h [i] ;
	for ( int i = 1 ; i <= n ; i ++ ) {
		cin >> w [i] ; 
		sw [i] = sw [i-1] + w [i] ; 
	}
	
	dp [1] = 0 ; 
	add_lichao (1) ; 
	
	for ( int i = 2 ; i <= n ; i ++ ) 
	{
		dp [i] = T.get(2*h[i]) + sqr (h[i]) + sw [i-1] ; 
		add_lichao (i) ; 
	}
	
	cout << dp [n] ; 
}
 
// range , error , check special , ... 
// find key , find key 
//'-std=c++11' stay hard 
// there is no tomorrow 

Compilation message (stderr)

building.cpp: In function 'void rf()':
building.cpp:34:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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