제출 #74436

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
74436		mjt	Mountains (IOI17_mountains)	C++11	0 / 100	2 ms	608 KiB

mountains

#include"mountains.h"
#include<bits/stdc++.h>
using namespace std;

const int N = 2010;
int y[N];
int f[N][N];

bool Judge(int a,int b,int c) { // a see c ?
	// ((y[a] - y[b]) / (a - b)) > ((y[a] - y[c]) / (a - c));
	return 1ll * (y[a] - y[b]) * (a - c) >= 1ll * (y[a] - y[c]) * (a - b);
}

int solve(int l,int r) {
	if (f[l][r]) return f[l][r];
	if (l > r) return 0;
	if (l == r) return 1;
	int pos = -1, mx = -1;
	for (int i=l; i<=r; ++i) if (y[i] > mx) pos = i, mx = y[i];
	int ans1 = solve(l, pos - 1) + solve(pos + 1, r);
	
	int ans2 = 0;
	for (int i=pos-1,j; i>=l; i=j) {
		for (j=i-1; j>=l; --j) {
			if (Judge(j, i, pos)) {
				if (j == l) ans2 += solve(l, i - 1);
				continue;
			}
			if (j + 1 <= i - 1) ans2 += solve(j + 1, i - 1);
			break;
		}
	}
	for (int i=pos+1,j; i<=r; i=j) {
		for (j=i+1; j<=r; ++j) {
			if (Judge(pos, i, j)) {
				if (j == r) ans2 += solve(i + 1, r);
				continue;
			}
			if (i + 1 <= j - 1) ans2 += solve(i + 1, j - 1);
			break;
		}
	} 
	return f[l][r] = max(ans1, ans2 + 1);
}

int maximum_deevs(vector<int> A) {
	int n = A.size();
	for (int i=1; i<=n; ++i) y[i] = A[i - 1];
	return solve(1, n);
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30