709902. Find k-th smallest element in given n ranges
Medium
Here is the detailed Markdown blog post for the problem:
Find k-th smallest element in given n ranges
Summary
Given n number of ranges, find the k-th smallest element. This problem involves searching and sorting algorithms to solve.
Detailed Explanation
The problem can be solved by first merging all the ranges into a single array. Then, sort this array in ascending order. After that, iterate through the sorted array until we reach the k-th element, which is our desired result.
Here's a step-by-step breakdown of the solution:
- Create an empty array to store all the ranges.
- Iterate through each range and add its elements to the array.
- Sort the array in ascending order.
- Initialize a counter variable to 0.
- Iterate through the sorted array until we reach the
k-thelement. - Return the
k-thelement as our result.
Time complexity: O(n log n) due to sorting Space complexity: O(n) for storing all the ranges
Optimized Solutions
Java
import java.util.Arrays;
import java.util.Comparator;
public class FindKthSmallest {
public static int findKthSmallest(int[][] ranges, int k) {
// Create an empty array to store all the ranges.
int[] arr = new int[ranges.length * (ranges[0].length + 1)];
int index = 0;
// Iterate through each range and add its elements to the array.
for (int i = 0; i < ranges.length; i++) {
for (int j = 0; j < ranges[i].length; j++) {
arr[index++] = ranges[i][j];
}
}
// Sort the array in ascending order.
Arrays.sort(arr);
// Initialize a counter variable to 0.
int count = 0;
// Iterate through the sorted array until we reach the k-th element.
for (int i = 0; i < arr.length; i++) {
if (count == k - 1) {
return arr[i];
}
count++;
}
// Return the k-th element as our result.
return arr[arr.length - 1];
}
}