77. Combinations | Leetcode | Medium | Java | Backtracking | Hindi | Top Interview 150

The "Combinations" problem is a renowned challenge featured in LeetCode's Top Interview 150 problems, specifically categorized under the backtracking section. The core idea revolves around employing the pick-and-not-pick technique, a widely recognized and employed method for generating all subsets of an array with a specific length, k.

The process is orchestrated through a recursive function, a cornerstone in backtracking algorithms, to systematically discover all combinations. Here's an in-depth breakdown of the methodology:

Recursive Function Foundation:
The journey commences with the establishment of a recursive function. This function is designed to navigate through the array elements, making decisions at each step regarding inclusion or exclusion in the current combination.
Base Case Establishment:
A pivotal aspect of the recursive function is the incorporation of a base case. This condition typically triggers when the size of the current combination matches the desired length, k. Upon meeting this criterion, the current combination is appended to the list of final results.
Decision-Making Process:
Within the recursive function's framework, the decision-making process unfolds:
When opting to include an element in the combination, it is added to the list, and the index is incremented for subsequent iterations.
Conversely, if an element is excluded from the combination, the process seamlessly proceeds to the next element without altering the current combination.
Integrating Backtracking:
The essence of backtracking emerges prominently during this exploration. After each decision (whether to pick or not pick an element), a backtrack occurs by removing the most recently added element from the combination. This pivotal step ensures a comprehensive exploration of all possible combinations, mitigating the risk of duplicates or overlooking potential combinations.
Recursion Continuity:
The recursive function perseveres until all elements have been evaluated or until the desired length, k, has been reached within the combination. Subsequently, the finalized combination is appended to the collection of results.
Realization of Results:
Upon completion of the recursive function's execution, a comprehensive list of all combinations adhering to the specified length criterion, k, is at our disposal.

Other problems for practice:

[audiosniperrofficial]

and if possible please do potd as you do in java i need it

[audiosniperrofficial]

can you mention your leetcode and github profile