Learn to implement Dijkstras Algorithm with a Priority Queue using a min-heap (heapq). We cover the problem statement, clear intuition, step-by-step approach, fully commented code, a hand dry-run, Big-O analysis, and key takeaways.<\/p>\n\n\n\n
Here’s the [Problem Link<\/span><\/mark><\/a><\/strong>] to begin with.<\/p>\n\n\n For a weighted directed<\/strong> graph with non-negative edge weights, return an array Although the original GFG statement shows an adjacency matrix<\/em>, we\u2019ll solve with a more memory-friendly adjacency list<\/strong>; the core logic is identical.<\/p>\n\n\n\n1. What does the problem ask?<\/h2>\n\n\n\n
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dist<\/code> wheredist[i]<\/code> = length of the shortest path<\/strong> from a given source vertex src<\/code> to vertex i<\/code>.
If a vertex is unreachable, keep its distance as \u221e<\/code> (or any sentinel like float('inf')<\/code>).<\/p>\n<\/blockquote>\n\n\n\n
\n\n\n\n2. Example<\/h2>\n\n\n\n