In this tutorial, I am going to discuss a very interesting problem Product of array except self or product of every integer except the integer at that index.
Given an array of N integers where N > 1. Write a code to print the result/output such that result[i] is equal to the product of all the elements of an array except self (result[i]).
For example –
Input: {4, 2, 1, 7}
Output: {14, 28, 56, 8}
NOTE: We have to solve this problem without division and in linear time O(n).
Find top k frequent elements in an array of integers. Let’s first understand the problem statement and the we will solve this problem using multiple approaches.
Given a non-empty array of integers, return the k most frequent elements.
Example 1:
Input: arr = {3, 4, 4, 4, 7, 7}, k = 2
Output: {4, 7}
Two most frequent elements are 4 and 7.
Example 2:
Input: arr = {3}, k = 1
Output: {3}
NOTE:
* k is always valid, 1 ≤ k ≤ number of unique elements.
* The time complexity must be better than O(nlogn), where n is the array’s size.
* It’s guaranteed that the answer is unique, in other words, the set of the top k frequent elements is unique.
* Answer can be returned in any order.
Given a singly linked list, write a code to reverse a linked list. In this tutorial, you are going to learn how to reverse a linked list in java using iterative approach.
For example –
Input linked list.
15 -> 9 -> 8 -> 5 -> NULL
When we reverse this linked list then the output is given below.
5 -> 8 -> 9 -> 15 -> NULL
In input linked list, head points to a node whose value is 15 but when it’s reversed the head points to a node whose value is 5.