Submission #343681

#	Time	Username	Problem	Language	Result	Execution time	Memory
343681		_ani	K blocks (IZhO14_blocks)	C++17	100 / 100	656 ms	82788 KiB

blocks

#define BUGO(x) cerr << #x << " = " << (x) << '\n';
#include <iostream>
#include <algorithm>
#include <stack>
#include <vector>
using namespace std;
using ll = long long;
const int N = 100'002;
const int K = 20;
const ll inf = 1'000'000'000'000'000'000LL;
ll dp[N][102], a[N];
struct el {
    ll x; int ind;
};
bool operator<(const el& a, const el& b) {
    return a.x < b.x;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, k;
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    for (int i = 0; i <= n; i++)
        for (int curk = 1; curk <= k; curk++)
            dp[i][curk] = inf;

    for (int curk = 1; curk <= k; curk++) {
        stack<el> x;
        vector<int> mn;
        x.push({ inf, 0 });
        for (int i = 1; i <= n; i++) {
            while (!mn.empty() && dp[mn.back()][curk - 1] > dp[i - 1][curk - 1])
                mn.erase(prev(mn.end()));
            if (i > 1)
                mn.push_back(i - 1);
            while (x.top().x < a[i])x.pop();
            el prev = x.top();
            x.push({ a[i], i });
            if (i < curk) {
                continue;
            }
            if (curk == 1)
                dp[i][curk] = ((i - 1 != 0) ? max(dp[i - 1][1], a[i]) : a[i]);
            else if (prev.ind == 0) {
                if (i - 1 == 0)
                    dp[i][curk] = a[i];
                else {
                    int x = lower_bound(mn.begin(), mn.end(), 1) - mn.begin();
      //              cerr << x << '\n';
                    dp[i][curk] = a[i] + dp[mn[x]][curk - 1];
                }
            }
            else {
                int x = lower_bound(mn.begin(), mn.end(), prev.ind) - mn.begin();
    //            cerr << x << '\n';
                dp[i][curk] = min(dp[prev.ind][curk], dp[mn[x]][curk - 1] + a[i]);
            }
        }
    }

  /*  for (int i = 0; i <= n; i++)
    {
        for (int curk = 0; curk <= k; curk++)
            cerr << dp[i][curk] << ' ';
        cerr << '\n';
    }*/
    cout << dp[n][k] << '\n';
    return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 47 / 47