sum of subset

[Sidhijain]

solved #2067 issue

Subset sum problem is to find subset of elements that are selected from a given set whose sum adds up to a given number K.

Language Used:c++

[Mention the Language of Code]

Checklist:

• [x] I have placed my code file in the (/Code) Folder e.g. If it's a Code in JAVA then I have placed my code pr_name.java file in (/Code/Java/) Directory.
• [x] I have Added the Description, Approach, and Working of Code at the beginning of Code.
• [x] I have added 2 or more Testcases at the Bottom side of the Code.
• [x] I have Added Time and Space Complexity at the End of the Code.
• [x] I have Explained the Variables use in Complexity e.g. O(n) where n is the length of an array.
• [x] I have Updated the Readme Related to the Topics e.g., if the issue is regarding Matrix then Update the Readme.MD present in 2D_Array Folder.
• [x] I have added Proper Comments in between the Code for Better Explanation.
• [x] I have sorted the list of the Readme.MD where I have added the issue in the Alphabetical Order.

[github-actions[bot]]

AlgoTree team will review your PR soon. Take Care of Few of the Things where most contributors are missing out. @Sidhijain :)