124. Create a Specific Triangle Pattern from an Array

Objective: Given an array of integers such that the first level will print all the elements in the array and from then at each level, the number of elements will be one less than the previous level, and elements at the level will be the Sum of consecutive elements in the previous level. Print it in a reverse level. See Example.

Example:

Approach:

• Recursion is the key.
• At each iteration create a new array that contains the Sum of consecutive elements in the array passes as a parameter.
• Make a recursive call and pass the newly created array in the previous step.
• While backtracking print the array (for printing in reverse order)

Output:

[48]
[20, 28]
[8, 12, 16]
[3, 5, 7, 9]
[1, 2, 3, 4, 5]

Related Problems:

- Elements in an Array Occurring More Than N/K Times Hard
- Find Maximum Consecutive Ones in an Array Beginner
- Find Subarray with Sum Equal to a Target Value Medium
- Check if array contains all unique or distinct numbers Beginner
- Count and print all Subarrays with product less than K in O(n) Hard