Untitled

import java.util.*;

class Solution {
    public int maxEvents(int[][] events) {
        // Sort events by start day
        Arrays.sort(events, (a, b) -> a[0] - b[0]);
        
        PriorityQueue<Integer> minHeap = new PriorityQueue<>();
        int attended = 0;
        int day = 0;
        int i = 0;
        int n = events.length;
        
        // Iterate through days
        while (i < n || !minHeap.isEmpty()) {
            // Move to the next available day
            if (minHeap.isEmpty()) {
                day = events[i][0];
            }
            
            // Add all events that start on or before the current day
            while (i < n && events[i][0] <= day) {
                minHeap.offer(events[i][1]); // Add event's end day to the heap
                i++;
            }
            
            // Remove events that have expired (end day < current day)
            while (!minHeap.isEmpty() && minHeap.peek() < day) {
                minHeap.poll();
            }
            
            // Attend the event that ends the earliest
            if (!minHeap.isEmpty()) {
                minHeap.poll(); // Attend the event
                attended++;
                day++; // Move to the next day
            }
        }
        
        return attended;
    }
}