Renamed file dijkstra

algorithms/Python/README.md

@@ -77,6 +77,7 @@
 - [Simple Graph](graphs/graph.py)
 - [BFS SEQUENCE](graphs/bfs-sequence.py)
 - [Depth First Search](graphs/depth-first-search.py)
+- [Dijkstra's Algorithm](graphs/dijkstra.py)
 
 ## Trees
 - [Binary Tree](trees/binary_tree.py)

algorithms/Python/graphs/python-dijsktra.py

@@ -1,110 +0,0 @@
-# A Dijkstra's algorithm implementation in Python
-# using adjacency matrix
-
-from math import inf
-
-wmat = [[0, 2, 0, 0, 0, 1, 0, 0],
-        [2, 0, 2, 2, 4, 0, 0, 0],
-        [0, 2, 0, 0, 3, 0, 0, 1],
-        [0, 2, 0, 0, 4, 3, 0, 0],
-        [0, 4, 3, 4, 0, 0, 7, 0],
-        [1, 0, 0, 3, 0, 0, 5, 0],
-        [0, 0, 0, 0, 7, 5, 0, 6],
-        [0, 0, 1, 0, 0, 0, 6, 0]]
-
-
-def find_all(wmat, start, end=-1):
-    """
-    Returns a tuple with a distances' list and paths' list of
-    all remaining vertices with the same indexing.
-
-        (distances, paths)
-
-    For example, distances[x] are the shortest distances from x
-    vertex which shortest path is paths[x]. x is an element of
-    {0, 1, ..., n-1} where n is the number of vertices
-
-    Args:
-    wmat    --  weighted graph's adjacency matrix
-    start   --  paths' first vertex
-    end     --  (optional) path's end vertex. Return just the 
-                distance and its path
-
-    Exceptions:
-    Index out of range, Be careful with start and end vertices
-    """
-    n = len(wmat)
-
-    dist = [inf]*n
-    dist[start] = wmat[start][start]  # 0
-
-    spVertex = [False]*n
-    parent = [-1]*n
-
-    path = [{}]*n
-
-    for count in range(n-1):
-        minix = inf
-        u = 0
-
-        for v in range(len(spVertex)):
-            if spVertex[v] == False and dist[v] <= minix:
-                minix = dist[v]
-                u = v
-
-        spVertex[u] = True
-        for v in range(n):
-            if not(spVertex[v]) and wmat[u][v] != 0 and dist[u] + wmat[u][v] < dist[v]:
-                parent[v] = u
-                dist[v] = dist[u] + wmat[u][v]
-
-    for i in range(n):
-        j = i
-        s = []
-        while parent[j] != -1:
-            s.append(j)
-            j = parent[j]
-        s.append(start)
-        path[i] = s[::-1]
-
-    return (dist[end], path[end]) if end >= 0 else (dist, path)
-
-
-def find_shortest_path(wmat, start, end=-1):
-    """
-    Returns paths' list of all remaining vertices.
-
-    Args:
-    wmat    --  weigthted graph's adjacency matrix
-    start   --  paths' first vertex
-    end     --  (optional) path's end vertex. Return just
-                the path
-
-    Exceptions:
-    Index out of range, Be careful with start and end vertices.
-    """
-    return find_all(wmat, start, end)[1]
-
-
-def find_shortest_distance(wmat, start, end=-1):
-    """
-    Returns distances' list of all remaining vertices.
-
-    Args:
-    wmat    --  weigthted graph's adjacency matrix
-    start   --  paths' first vertex
-    end     --  (optional) path's end vertex. Return just
-                the distance
-
-    Exceptions:
-    Index out of range, Be careful with start and end vertices.
-    """
-    return find_all(wmat, start, end)[0]
-
-if __name__ == "__main__":
-    i = 0
-    for D, P in zip(*find_all(wmat, 0)):
-        print("Target: {}, Distance: {}, Path: {}".format(i, D, P))
-        i += 1
-    print("\nshortest path to last node", find_shortest_path(wmat, 0, 7))
-    print("shortest distance to last node", find_shortest_distance(wmat, 0, 7))