Submission #232047

#	Time	Username	Problem	Language	Result	Execution time	Memory
232047		infinite_iq	Mountains (IOI17_mountains)	C++14	100 / 100	40 ms	14208 KiB

mountains

#define fast ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#include <bits/stdc++.h>
using namespace std;
#define sqr 270
//#define mp make_pair
#define mid (l+r)/2
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define ins insert
#define era erase
#define C continue
#define mem(dp,i) memset(dp,i,sizeof(dp))
#define mset multiset
#define all(x) x.begin(), x.end()
#define gc getchar_unlocked
typedef long long ll;
typedef short int si;
typedef long double ld;
typedef pair<int,int> pi;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
const ll inf=1e18;
const ll mod=1e9+7;
const ld pai=acos(-1);
#include "mountains.h"
pll a [2009] ;
int dp [2009][2009] ;
bool seen ( pll a , pll b , pll c ) {
        return ( ( (b.fi - a.fi) * (c.se - a.se) - (b.se - a.se) * (c.fi - a.fi) ) >= 0 ) ;
}
int maximum_deevs ( vi v ) {
        int n = v.size () ;
        for ( int i = 0 ; i < n ; i ++ ) {
                a[i] .fi = i ;
                a[i] .se = v [i] ;
        }
        for ( int r = 0 ; r < n ; r ++ ) {
                int sum = 0 , last = r ;
                dp [r][r] = 1 ;
                for ( int l = r - 1 ; l >= 0 ; l -- ) {
                        dp [l][r] = dp [l][r-1] ;
                        if ( seen ( a [l] , a [last] , a [r] ) ) {
                                sum += dp [l+1][last-1] ;
                                last = l ;
                        }
                        dp [l][r] = max ( dp [l][r] , dp [l][last-1] + sum + 1 ) ;
                }
        }
  		return dp [0][n-1] ; 
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30