DSA Python 2025 - Why Use Priority Queue and not Queue in Dijkstra’s Algorithm? | Part 146

🚀 Welcome to Part 146 of Code & Debug’s DSA Python Course 2025!

In this session, we answer a very important and commonly asked question:

❓ "Why do we use a Priority Queue in Dijkstra’s Algorithm instead of a normal Queue?"

🔍 What you’ll learn:
✅ What goes wrong if you use a normal queue in Dijkstra
✅ How the priority queue helps always pick the minimum distance node
✅ Real-world example & dry run comparisons
✅ Why Dijkstra with a normal queue breaks the greedy property
✅ Time Complexity: O(E log V) of PQ-based approach – full breakdown
✅ Interview-level clarity on why heap is crucial

📄 Topics Covered:
• Dijkstra with Queue: Wrong outputs
• Priority Queue (Min Heap): Correctness + Efficiency
• heapq in Python
• Detailed comparison: Queue vs PQ
• Why O(E log V) is optimal

📚 Complete Python DSA Playlist & Sheet:

🚀 Master DSA Live from Scratch:

💡 Free Problem-Solving Masterclass (Leetcode-Based):

👀 Still using a queue in Dijkstra? Let’s fix that today.
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#DijkstraAlgorithm #PriorityQueue #WhyNotQueue #GraphsInPython #DSATimeComplexity #OElgV #GreedyAlgorithms #CodeAndDebug #Part146 #PythonDSA2025

[deepeshsharma]

This full Python DSA playlist is totally worth it to watch. 🔥Thank you so much Sir ! ❤

[omkarchougule]

Thank you so much for this series. Please keep it up. ❤

[SamG-dcjq]

sir please dont stop like some other teachers i am gonna start this course now.
please dont stop it before ending it

[prakharnema]

how many lectures are left in this dsa series? and like when will it end, any approx date?

[DivyanshSingh-fz]

How many videos are we projected to end this playlist at?