Submission #384790

#	Time	Username	Problem	Language	Result	Execution time	Memory
384790		apostoldaniel854	Mountains (IOI17_mountains)	C++14	0 / 100	1 ms	364 KiB

mountains

#include <bits/stdc++.h>

using namespace std;

//#define HOME


#ifndef HOME
#include "mountains.h"
#endif // HOME

using ll = long long;

struct point_t {
    int x;
    int y;
};
/**
6
6 1 5 2 3 1

**/
const int MAX_N = 2000;
point_t p[1 + MAX_N];
int dp[1 + MAX_N][1 + MAX_N];

ll area (point_t a, point_t b, point_t c) {
    return 1ll * a.x * a.y + 1ll * b.x * c.y + 1ll * c.x * a.y - 1ll * a.y * c.x - 1ll * b.y * a.x - 1ll * c.y * b.x;
}

int maximum_deevs(std::vector<int> y) {
    int n = y.size ();
	for (int i = 1; i <= n; i++)
        p[i] = {i, y[i - 1]};
    for (int i = 1; i <= n; i++) {
        int k = i; dp[i][i] = 1;
        int offset = 0;
        for (int j = i - 1; j > 0; j--) {
            dp[j][i] = dp[j][i - 1];
            if (area (p[j], p[k], p[i]) >= 0)
                offset += dp[j + 1][k - 1], k = j;
            dp[j][i] = max (dp[j][i], 1 + offset + dp[j][k - 1]);
        }
    }
    return dp[1][n];
}


#ifdef HOME
int main() {
	int n;
	assert(1 == scanf("%d", &n));
	std::vector<int> y(n);
	for (int i = 0; i < n; i++) {
		assert(1 == scanf("%d", &y[i]));
	}
	int result = maximum_deevs(y);
	printf("%d\n", result);
	return 0;
}
#endif // HOME

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