|
1 | 1 | def print_dist(dist, v): |
2 | | - """ |
3 | | - Print vertex distances. |
4 | | - >>> print_dist([0.0, 5.0, 8.0, 9.0], 4) |
5 | | - Vertex Distance |
6 | | - 0 0 |
7 | | - 1 5 |
8 | | - 2 8 |
9 | | - 3 9 |
10 | | - >>> print_dist([0.0, float('inf')], 2) |
11 | | - Vertex Distance |
12 | | - 0 0 |
13 | | - 1 INF |
14 | | - >>> print_dist([0.0], 1) |
15 | | - Vertex Distance |
16 | | - 0 0 |
17 | | - """ |
18 | | - print("Vertex Distance") |
19 | | - for i in range(v): |
20 | | - if dist[i] != float("inf"): |
21 | | - print(i," ", int(dist[i])) |
22 | | - else: |
23 | | - print(i," ", "INF") |
| 2 | + """ |
| 3 | + Print vertex distances. |
| 4 | + >>> print_dist([0.0, 5.0, 8.0, 9.0], 4) |
| 5 | + Vertex Distance |
| 6 | + 0 0 |
| 7 | + 1 5 |
| 8 | + 2 8 |
| 9 | + 3 9 |
| 10 | + >>> print_dist([0.0, float('inf')], 2) |
| 11 | + Vertex Distance |
| 12 | + 0 0 |
| 13 | + 1 INF |
| 14 | + >>> print_dist([0.0], 1) |
| 15 | + Vertex Distance |
| 16 | + 0 0 |
| 17 | + """ |
| 18 | + print("Vertex Distance") |
| 19 | + for i in range(v): |
| 20 | + if dist[i] != float("inf"): |
| 21 | + print(i, " ", int(dist[i])) |
| 22 | + else: |
| 23 | + print(i, " ", "INF") |
24 | 24 |
|
25 | 25 |
|
26 | 26 | def min_dist(mdist, vset, v): |
27 | | - """ |
28 | | - Finds the vertex with minimum distance that hasn't been visited yet. |
29 | | - >>> min_dist([0, 4, 2, float('inf')], [True, False, False, False], 4) |
30 | | - 2 |
31 | | - >>> min_dist([0, 4, 2, 1], [True, False, True, False], 4) |
32 | | - 3 |
33 | | - >>> min_dist([0, 4, 2, 1], [True, True, True, True], 4) |
34 | | - -1 |
35 | | - >>> min_dist([float('inf'), float('inf')], [False, False], 2) |
36 | | - -1 |
37 | | - """ |
38 | | - min_val = float("inf") |
39 | | - min_ind = -1 |
40 | | - for i in range(v): |
41 | | - if (not vset[i]) and mdist[i] < min_val: |
42 | | - min_ind = i |
43 | | - min_val = mdist[i] |
44 | | - return min_ind |
| 27 | + """ |
| 28 | + Finds the vertex with minimum distance that hasn't been visited yet. |
| 29 | + >>> min_dist([0, 4, 2, float('inf')], [True, False, False, False], 4) |
| 30 | + 2 |
| 31 | + >>> min_dist([0, 4, 2, 1], [True, False, True, False], 4) |
| 32 | + 3 |
| 33 | + >>> min_dist([0, 4, 2, 1], [True, True, True, True], 4) |
| 34 | + -1 |
| 35 | + >>> min_dist([float('inf'), float('inf')], [False, False], 2) |
| 36 | + -1 |
| 37 | + """ |
| 38 | + min_val = float("inf") |
| 39 | + min_ind = -1 |
| 40 | + for i in range(v): |
| 41 | + if (not vset[i]) and mdist[i] < min_val: |
| 42 | + min_ind = i |
| 43 | + min_val = mdist[i] |
| 44 | + return min_ind |
45 | 45 |
|
46 | 46 |
|
47 | 47 | def dijkstra(graph, v, src): |
@@ -75,36 +75,36 @@ def dijkstra(graph, v, src): |
75 | 75 | vset = [False for _ in range(v)] |
76 | 76 | mdist[src] = 0.0 |
77 | 77 |
|
78 | | - for _ in range(v - 1): |
79 | | - u = min_dist(mdist, vset, v) |
80 | | - vset[u] = True |
| 78 | + for _ in range(v - 1): |
| 79 | + u = min_dist(mdist, vset, v) |
| 80 | + vset[u] = True |
81 | 81 |
|
82 | | - for i in range(v): |
83 | | - if ( |
84 | | - (not vset[i]) |
85 | | - and graph[u][i] != float("inf") |
86 | | - and mdist[u] + graph[u][i] < mdist[i] |
87 | | - ): |
88 | | - mdist[i] = mdist[u] + graph[u][i] |
| 82 | + for i in range(v): |
| 83 | + if ( |
| 84 | + (not vset[i]) |
| 85 | + and graph[u][i] != float("inf") |
| 86 | + and mdist[u] + graph[u][i] < mdist[i] |
| 87 | + ): |
| 88 | + mdist[i] = mdist[u] + graph[u][i] |
89 | 89 |
|
90 | | - print_dist(mdist, v) |
| 90 | + print_dist(mdist, v) |
91 | 91 |
|
92 | 92 |
|
93 | 93 | if __name__ == "__main__": |
94 | | - V = int(input("Enter number of vertices: ").strip()) |
95 | | - E = int(input("Enter number of edges: ").strip()) |
| 94 | + V = int(input("Enter number of vertices: ").strip()) |
| 95 | + E = int(input("Enter number of edges: ").strip()) |
96 | 96 |
|
97 | | - graph = [[float("inf") for i in range(V)] for j in range(V)] |
| 97 | + graph = [[float("inf") for i in range(V)] for j in range(V)] |
98 | 98 |
|
99 | | - for i in range(V): |
100 | | - graph[i][i] = 0.0 |
| 99 | + for i in range(V): |
| 100 | + graph[i][i] = 0.0 |
101 | 101 |
|
102 | | - for i in range(E): |
103 | | - print("\nEdge ", i + 1) |
104 | | - src = int(input("Enter source:").strip()) |
105 | | - dst = int(input("Enter destination:").strip()) |
106 | | - weight = float(input("Enter weight:").strip()) |
107 | | - graph[src][dst] = weight |
| 102 | + for i in range(E): |
| 103 | + print("\nEdge ", i + 1) |
| 104 | + src = int(input("Enter source:").strip()) |
| 105 | + dst = int(input("Enter destination:").strip()) |
| 106 | + weight = float(input("Enter weight:").strip()) |
| 107 | + graph[src][dst] = weight |
108 | 108 |
|
109 | | - gsrc = int(input("\nEnter shortest path source:").strip()) |
110 | | - dijkstra(graph, V, gsrc) |
| 109 | + gsrc = int(input("\nEnter shortest path source:").strip()) |
| 110 | + dijkstra(graph, V, gsrc) |
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