Kth Smallest Number in M Sorted Lists
Explore how to efficiently find the kth smallest number across multiple sorted lists by applying k-way merge strategies. Learn to handle duplicates, boundary cases, and optimize the search for coding interview challenges.
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Statement
Given a list, lists, containing k, find the
Even if some values appear multiple times across the lists, each occurrence is treated as a unique element when determining the
If k exceeds the total number of elements across all lists, return the largest element among them. If the lists are empty, return 0.
Constraints:
-
lists[i].length -
lists[i][j] -
k
Examples
Understand the problem
Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:
Smallest Number in Sorted Lists
What is the output if the following lists and the value of k are given as input?
list1 = [1, 4, 5]
list2 = [4, 7, 8]
list3 = [2, 6, 9]
k = 5
7
5
6
Figure it out!
We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.
Try it yourself
Implement your solution in KthSmallest.cpp in the following coding playground.
#include <iostream>#include <vector>#include <queue>int KSmallestNumber(std::vector<std::vector<int>> list, int k){// Replace this placeholder return statement with your codereturn -1;}