Submission #528941

#	Time	Username	Problem	Language	Result	Execution time	Memory
528941		tabr	Mountains (IOI17_mountains)	C++17	70 / 100	1067 ms	16056 KiB

mountains

#include <bits/stdc++.h>
using namespace std;
#ifdef tabr
#include "library/debug.cpp"
#else
#define debug(...)
#endif

int maximum_deevs(vector<int> y) {
    int n = (int) y.size();
    vector<vector<int>> dp(n + 1, vector<int>(n + 1));
    for (int l = n - 1; l >= 0; l--) {
        for (int r = l + 1; r <= n; r++) {
            int pos = (int) (max_element(y.begin() + l, y.begin() + r) - y.begin());
            dp[l][r] = 1;
            int lst = pos;
            pair<int, int> a = make_pair(1, 0);
            for (int i = pos - 1; i >= l; i--) {
                auto b = make_pair(y[pos] - y[i], pos - i);
                if (1LL * a.first * b.second >= 1LL * a.second * b.first) {
                    a = b;
                    dp[l][r] += dp[i + 1][lst];
                    lst = i;
                }
            }
            dp[l][r] += dp[l][lst];
            lst = pos;
            a = make_pair(1, 0);
            for (int i = pos + 1; i < r; i++) {
                auto b = make_pair(y[pos] - y[i], i - pos);
                if (1LL * a.first * b.second >= 1LL * a.second * b.first) {
                    a = b;
                    dp[l][r] += dp[lst + 1][i];
                    lst = i;
                }
            }
            dp[l][r] += dp[lst + 1][r];
            dp[l][r] = max(dp[l][r], dp[l][pos] + dp[pos + 1][r]);
        }
    }
    return dp[0][n];
}

#ifdef tabr
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    debug(maximum_deevs({6, 1, 5, 2, 3, 1}));
    debug(maximum_deevs({0, 1, 2}));
    return 0;
}
#endif

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