Submission #803268

#	Time	Username	Problem	Language	Result	Execution time	Memory
803268		Username4132	Mountains (IOI17_mountains)	C++14	100 / 100	25 ms	14164 KiB

mountains

#include "mountains.h"
#include <vector>
using namespace std;
using ll = long long;
#define forn(i, n) for(int i=0; i<(int)n; ++i)
#define forsn(i, s, n) for(int i=s; i<(int)n; ++i)
#define dforn(i, n) for(int i=n-1; i>=0; --i)
 
const int MAXN = 2010;
int n, dp[MAXN][MAXN];
 
bool clockwise(ll ax, ll bx, ll cx, ll ay, ll by, ll cy){
	return (ax*by + bx*cy + cx*ay - ay*bx - by*cx - cy*ax)>=0;
}
 
int maximum_deevs(vector<int> y) {
	n = y.size();
	dp[0][1]=1;
	forsn(i, 1, n){
		int lst = i-1, sum=1;
		dp[i][i+1]=1;
		dforn(j, i){
			if(clockwise(j, lst, i, y[j], y[lst], y[i])){
				sum+=dp[j+1][lst];
				lst=j;
			}
			dp[j][i+1]=max(sum+dp[j][lst], dp[j][i]);
		}
	}
	return dp[0][n];
}

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