Welcome to Day 7 of the DSA Coding Challenge:

Today's Goals (Backtracking continued) :

Question 1: Combinations Sum 2: Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target. Each number in candidates may only be used once in the combination. Note: The solution set must not contain duplicate combinations.

Question 2: Combinations Sum 3: Find all valid combinations of k numbers that sum up to n such that the following conditions are true:

•Only numbers 1 through 9 are used.

•Each number is used at most once.

Return a list of all possible valid combinations. The list must not contain the same combination twice, and the combinations may be returned in any order.

All the best !