Solving HackerRank Challenges

Learn how to solve the HackerRank problem whose title is Mini-Max Sum, using the Java programming language.

https://www.hackerrank.com/challenges/mini-max-sum

The Data Structures and Algorithms (DSA) lesson uses a running total approach to solving the question using Java.

Traversing the array, you can keep track of the sum so far, in addition to the highest and lowest numbers seen so far.

Then later you can determine the minimum sum by subtracting the highest number and the maximum sum by subtracting the lowest number.

The time complexity for the solution is O(n) and its space complexity is O(1).

DSA problems are sometimes asked during tech job interviews for positions such as Software Engineer, so you can use the challenge to practice that skill.

Mini-Max Sum - HackerRank - Java

Learn how to solve the HackerRank problem whose title is Reverse a linked list, using the Java programming language.

https://www.hackerrank.com/challenges/reverse-a-linked-list

The Data Structures and Algorithms (DSA) lesson uses a recursive approach to solving the question using Java.

Traversing the linked list, you can keep track of current and the previous values.

Then later as you reach the base case, you can return the previous. Then, the recursive calls starting from the end of the list set the current's next to point to the previous one, as it makes it way backward to the beginning of the list.

The time complexity for the solution is O(n) and its space complexity is O(n).

DSA problems are sometimes asked during tech job interviews for positions such as Software Engineer, so you can use the challenge to practice that skill.

Reverse a linked list - HackerRank - Java

Learn how to solve the HackerRank problem whose title is Plus Minus, using the Java programming language.

https://www.hackerrank.com/challenges/plus-minus

The Data Structures and Algorithms (DSA) lesson uses a running sum and loop to solving the question using Java.

Traversing the array, you can keep track of the count of positive and negative integers. The zero count can be calculated later by subtracting positive and negative count from the total number of elements in the array.

After getting the counts, you can calculate the ratio of each kind of count out of the total number of elements in the array.

The function doesn't return anything, but you have to print out the ratios in a specific order, in the specified format.

The time complexity for the solution is O(n) and its space complexity is O(1).

DSA problems are sometimes asked during tech job interviews for positions such as Software Engineer, so you can use the challenge to practice that skill.

Plus Minus - HackerRank - Java

Learn how to solve the HackerRank problem whose title is Print the Elements of a Linked List, using the Java programming language.

https://www.hackerrank.com/challenges/print-the-elements-of-a-linked-list

The Data Structures and Algorithms (DSA) lesson uses an iterative approach with a pointer variable and a loop.

Assign the Current Pointer to the head given by the function argument.

Print out the data property of the current node, so long the current node is not null.

To move the pointer to the next element in the list, reassign the value of Current Pointer to its dot next property.

The time complexity for the solution is O(n) and its space complexity is O(1).

DSA problems are sometimes asked during tech job interviews for positions such as Software Engineer, so you can use the challenge to practice that skill.
