Given a project represented as a set of methods and dependency relations, remove a method and determine which other methods can no longer remain in the project because they become disconnected from the required starting point.
Remove Methods From Project
gfgProblem
You are given a project consisting of several methods. Some methods call other methods, forming dependency relations. One method is designated as the entry point of the project.
You need to remove a chosen method from the project. After that removal, some other methods may no longer be reachable from the entry point, so they must also be removed.
Return the remaining methods after all affected methods are removed.
In other words, starting from the entry method, keep only the methods that are still reachable after deleting the specified method and everything that becomes unreachable because of it.
Clarification
- A method can depend on multiple other methods.
- Removing one method may cause a cascade of removals if some methods lose all valid paths from the entry point.
- The final answer should reflect the methods that are still part of the usable project.
Input Format
The input format is not strictly specified in the source metadata. A standard formulation is:
- an integer
nfor the number of methods - a directed list of dependency edges
u -> vmeaning methoducalls methodv - an entry method
start - a method
removethat must be deleted
Output Format
Return the set or list of methods that remain reachable from start after removing remove and any methods that become unreachable as a result.
Constraints
No official constraints are provided in the source metadata.
A typical interview version would use:
1 <= n <= $10^{5}$- dependency relations form a directed graph
- method identifiers are unique integers or strings
Example 1
Input
methods = [1,2,3,4,5] edges = [[1,2],[2,3],[2,4],[4,5]] start = 1 remove = 2
Output
[1]
Explanation
Once method 2 is removed, every method that depended on reaching 2 becomes unreachable from the entry method 1. Only the entry method itself remains.
Example 2
Input
methods = [1,2,3,4,5] edges = [[1,2],[1,3],[2,4],[3,5]] start = 1 remove = 4
Output
[1,2,3,5]
Explanation
Removing 4 does not affect reachability of the other methods. Methods 1, 2, 3, and 5 remain reachable from the entry method.
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