Submission #541304

#	Time	Username	Problem	Language	Result	Execution time	Memory
541304		Astollfo	Rabbit Carrot (LMIO19_triusis)	Java	100 / 100	276 ms	23496 KiB

triusis

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
import java.util.ArrayList;

public class triusis {  // any other name breaks the grader lmao
    public static void main(String[] args) throws IOException {
        BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer inital = new StringTokenizer(read.readLine());
        int poleNum = Integer.parseInt(inital.nextToken());
        int jumpHeight = Integer.parseInt(inital.nextToken());

        ArrayList<Integer> possUnchanged = new ArrayList<>();
        for (int p = 0; p < poleNum; p++) {
            int pole = Integer.parseInt(read.readLine());
            // only add if it has any hope of being unchanged
            if ((p + 1) * jumpHeight >= pole) {
                possUnchanged.add((p + 1) * jumpHeight - pole);
            }
        }
        System.out.println(poleNum - longestNondecSubseq(possUnchanged));
    }

    private static int longestNondecSubseq(ArrayList<Integer> arr) {
        ArrayList<Integer> minEndings = new ArrayList<>();
        for (int i : arr) {
            // find the latest spot we can insert it (because it just has to be nondecreasing)
            int pos = bisectRight(minEndings, i);
            // standard LIS protocol
            if (pos == minEndings.size()) {
                minEndings.add(i);
            } else {
                minEndings.set(pos, i);
            }
        }
        return minEndings.size();
    }

    private static int bisectRight(ArrayList<Integer> arr, int x) {
        int lo = 0;
        int hi = arr.size();
        while (lo < hi) {
            int mid = (lo + hi) / 2;
            if (x < arr.get(mid)) {
                hi = mid;
            } else {
                lo = mid + 1;
            }
        }
        return lo;
    }
}

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 28 / 28
• Subtask 4: 37 / 37