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Create Floyd_Warshall_Algorithm.py #474

Open sriganeshres opened 3 months ago

sriganeshres commented 3 months ago

Title: Explanation of Floyd-Warshall Algorithm for All-Pairs Shortest Path

Description: This document provides an in-depth explanation of the Floyd-Warshall algorithm, a dynamic programming approach used to find the shortest paths between all pairs of vertices in a weighted graph. The algorithm efficiently handles both positive and negative edge weights, making it suitable for various real-world applications.

Key Concepts and Steps:

  1. Initialization:

    • The algorithm initializes a distance matrix where each entry represents the shortest distance between two vertices.
    • Initially, distances between directly connected vertices are set to their respective edge weights, and all other distances are set to infinity.
    • Additionally, the diagonal entries are set to zero as the shortest distance from a vertex to itself is always zero.
  2. Dynamic Programming:

    • The algorithm iteratively considers all vertices as potential intermediate nodes in the shortest path between every pair of vertices.
    • For each intermediate vertex, it updates the distance matrix to find shorter paths if they exist.
    • The algorithm evaluates whether going through the intermediate vertex improves the shortest path distance between two vertices.
  3. Iterative Update:

    • The algorithm updates the distance matrix by considering all possible pairs of vertices and all possible intermediate vertices.
    • For each pair of vertices (i, j) and potential intermediate vertex k, it checks if the path from i to j through k is shorter than the current shortest path.
    • If so, it updates the distance matrix to reflect this shorter path.
  4. Complexity Analysis:

    • The time complexity of the Floyd-Warshall algorithm is O(V^3), where V is the number of vertices in the graph.
    • This makes it suitable for graphs with relatively small numbers of vertices but may become inefficient for very large graphs due to its cubic time complexity.

Applications and Considerations:

Overall, the Floyd-Warshall algorithm provides a powerful solution for finding the shortest paths between all pairs of vertices in a graph, offering versatility and accuracy in various applications. Understanding its principles and computational complexity aids in its effective utilization in real-world scenarios.

Additional Notes: