LeetCode 2893: Calculate Orders Within Each Interval
Problem Description
Explanation:
Given a list of orders with timestamps, we need to calculate the number of orders within each time interval.
To solve this problem, we can follow these steps:
- Create a TreeMap to store the count of orders for each timestamp.
- Iterate through the list of orders and update the count in the TreeMap.
- Calculate the cumulative count of orders for each timestamp interval.
- Return the list of counts for each interval.
Time Complexity: O(n log n) where n is the number of orders. Space Complexity: O(n) for the TreeMap. :
Solutions
import java.util.*;
class Solution {
public List<Integer> countOrders(int[][] orders) {
TreeMap<Integer, Integer> map = new TreeMap<>();
for (int[] order : orders) {
map.put(order[0], map.getOrDefault(order[0], 0) + 1);
map.put(order[1] + 1, map.getOrDefault(order[1] + 1, 0) - 1);
}
int count = 0;
List<Integer> result = new ArrayList<>();
for (int val : map.values()) {
count += val;
result.add(count);
}
return result;
}
}Loading editor...