Add Topological Sorting using DFS (Issue #6938)#7389
Add Topological Sorting using DFS (Issue #6938)#7389Senrian wants to merge 2 commits intoTheAlgorithms:masterfrom
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Issue TheAlgorithms#7356: Add null check for the search value to prevent potential NullPointerException.
Senrian
requested review from
DenizAltunkapan,
alxkm and
yanglbme
as code owners
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| package com.thealgorithms.datastructures.queues | |||
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A semicolon (;) is missing at the end.
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| private Node<T> fromt; | ||
| private Node<T> rear,; |
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There’s an extra comma after rear.
| } | ||
| } | ||
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| private Node<T> fromt; |
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Did you mean 'front' instead of 'fromt'?
| throw new IllegalArgumentException("Cannot enqueue null data"); | ||
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| Node<T> newNode = new Node><T>(data); |
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There’s an extra > here.
Fix: Node newNode = new Node<>(data);
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| @Override | ||
| public synchronized T"next() { |
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Please remove the "
Fix: public synchronized T next() {
| return "[]"; | ||
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| StringBuilder sb = new StringBuilder("[[]"); |
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Did you mean "StringBuilder sb = new StringBuilder("[");" ?
| * @return an iterator over the elements in the queue | ||
| */ | ||
| @Override | ||
| public synchronized Iterator<T> iterator() { |
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The iterator is not fully thread-safe; it only captures the current state of front and may behave inconsistently under concurrent modifications.
| * @return a string representation of the queue | ||
| */ | ||
| @Override | ||
| public synchronized String toString() { |
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Calling isEmpty() inside other synchronized methods is redundant, since those methods already hold the lock. This doesn’t cause correctness issues, but it adds unnecessary synchronization overhead.
2 participants
Description
Implements topological sorting using Depth-First Search (DFS) for TheAlgorithms/Java repository, addressing issue #6938.
Algorithm
Given a Directed Acyclic Graph (DAG), the algorithm:
Complexity
Files
TopologicalSort.java- DFS-based topological sort implementationTopologicalSortTest.java- Comprehensive testsCloses #6938