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| 1 | +# Copyright (C) Deepali Srivastava - All Rights Reserved |
| 2 | +# This code is part of DSA course available on CourseGalaxy.com |
| 3 | + |
| 4 | +class Vertex: |
| 5 | + def __init__(self, name): |
| 6 | + self.name = name |
| 7 | + |
| 8 | + |
| 9 | +class DirectedGraph: |
| 10 | + |
| 11 | + def __init__(self,size=20): |
| 12 | + self._adj = [ [0 for column in range(size)] for row in range(size) ] |
| 13 | + self._n = 0 |
| 14 | + self._vertexList = [] |
| 15 | + |
| 16 | + |
| 17 | + def display(self): |
| 18 | + for i in range(self._n): |
| 19 | + for j in range(self._n): |
| 20 | + print( self._adj[i][j], end =' ') |
| 21 | + print() |
| 22 | + |
| 23 | + |
| 24 | + def numVertices(self): |
| 25 | + return self._n |
| 26 | + |
| 27 | + |
| 28 | + def numEdges(self): |
| 29 | + e = 0 |
| 30 | + for i in range(self._n): |
| 31 | + for j in range(self._n): |
| 32 | + if self._adj[i][j]!=0: |
| 33 | + e+=1 |
| 34 | + return e |
| 35 | + |
| 36 | + |
| 37 | + def vertices(self): |
| 38 | + return [vertex.name for vertex in self._vertexList] |
| 39 | + |
| 40 | + |
| 41 | + def edges(self): |
| 42 | + edges = [] |
| 43 | + for i in range(self._n): |
| 44 | + for j in range(self._n): |
| 45 | + if self._adj[i][j] != 0: |
| 46 | + edges.append( (self._vertexList[i].name, self._vertexList[j].name) ) |
| 47 | + return edges |
| 48 | + |
| 49 | + |
| 50 | + def _getIndex(self,s): |
| 51 | + index = 0 |
| 52 | + for name in (vertex.name for vertex in self._vertexList): |
| 53 | + if s == name: |
| 54 | + return index |
| 55 | + index += 1 |
| 56 | + return None |
| 57 | + |
| 58 | + |
| 59 | + def insertVertex(self,name): |
| 60 | + if name in (vertex.name for vertex in self._vertexList): ######## |
| 61 | + print("Vertex with this name already present in the graph") |
| 62 | + return |
| 63 | + |
| 64 | + self._vertexList.append( Vertex(name) ) |
| 65 | + self._n += 1 |
| 66 | + |
| 67 | + |
| 68 | + def removeVertex(self,name): |
| 69 | + u = self._getIndex(name) |
| 70 | + if u is None: |
| 71 | + print("Vertex not present in the graph") |
| 72 | + return |
| 73 | + |
| 74 | + self._adj.pop(u) |
| 75 | + |
| 76 | + for i in range(self._n): |
| 77 | + self._adj[i].pop(u) |
| 78 | + |
| 79 | + self._vertexList.pop(u) |
| 80 | + self._n -= 1 |
| 81 | + |
| 82 | + |
| 83 | + def insertEdge(self, s1, s2): |
| 84 | + u = self._getIndex(s1) |
| 85 | + v = self._getIndex(s2) |
| 86 | + if u is None: |
| 87 | + print("Start vertex not present in the graph, first insert the start vertex") |
| 88 | + elif v is None: |
| 89 | + print("End vertex not present in the graph, first insert the end vertex") |
| 90 | + elif u == v: |
| 91 | + print("Not a valid edge") |
| 92 | + elif self._adj[u][v] != 0 : |
| 93 | + print("Edge already present in the graph") |
| 94 | + else: |
| 95 | + self._adj[u][v] = 1 |
| 96 | + |
| 97 | + |
| 98 | + def removeEdge(self, s1,s2): |
| 99 | + u = self._getIndex(s1) |
| 100 | + v = self._getIndex(s2) |
| 101 | + if u is None: |
| 102 | + print("Start vertex not present in the graph") |
| 103 | + elif v is None: |
| 104 | + print("End vertex not present in the graph") |
| 105 | + elif self._adj[u][v] == 0: |
| 106 | + print("Edge not present in the graph") |
| 107 | + else: |
| 108 | + self._adj[u][v] = 0 |
| 109 | + |
| 110 | + |
| 111 | + def isAdjacent(self, s1, s2): |
| 112 | + u = self._getIndex(s1) |
| 113 | + v = self._getIndex(s2) |
| 114 | + if u is None: |
| 115 | + print("Start vertex not present in the graph") |
| 116 | + return False |
| 117 | + elif v is None: |
| 118 | + print("End vertex not present in the graph") |
| 119 | + return False |
| 120 | + return False if self._adj[u][v] == 0 else True |
| 121 | + |
| 122 | + |
| 123 | + def outdegree(self, s): |
| 124 | + u = self._getIndex(s) |
| 125 | + if u is None: |
| 126 | + print("Vertex not present in the graph") |
| 127 | + return |
| 128 | + |
| 129 | + outd = 0 |
| 130 | + for v in range(self._n): |
| 131 | + if self._adj[u][v] != 0 : |
| 132 | + outd+=1 |
| 133 | + return outd |
| 134 | + |
| 135 | + |
| 136 | + def indegree(self, s): |
| 137 | + u = self._getIndex(s) |
| 138 | + if u is None: |
| 139 | + print("Vertex not present in the graph") |
| 140 | + return |
| 141 | + |
| 142 | + ind = 0 |
| 143 | + |
| 144 | + for v in range(self._n): |
| 145 | + if self._adj[v][u] != 0 : |
| 146 | + ind+=1 |
| 147 | + return ind |
| 148 | + |
| 149 | + |
| 150 | + def warshalls(self): |
| 151 | + |
| 152 | + p = [ [0 for column in range(self._n)] for row in range(self._n) ] |
| 153 | + |
| 154 | + for i in range(self._n): |
| 155 | + for j in range(self._n): |
| 156 | + p[i][j] = self._adj[i][j] |
| 157 | + |
| 158 | + for k in range(self._n): |
| 159 | + for i in range(self._n): |
| 160 | + for j in range(self._n): |
| 161 | + p[i][j] = p[i][j] or ( p[i][k] and p[k][j] ) |
| 162 | + |
| 163 | + |
| 164 | + for i in range(self._n): |
| 165 | + for j in range(self._n): |
| 166 | + if p[i][j] != 0: |
| 167 | + print("1", end =" ") |
| 168 | + else: |
| 169 | + print("0", end =" ") |
| 170 | + print() |
| 171 | + print() |
| 172 | + |
| 173 | + |
| 174 | +if __name__ == '__main__': |
| 175 | + |
| 176 | + g1 = DirectedGraph() |
| 177 | + |
| 178 | + g1.insertVertex("Zero") |
| 179 | + g1.insertVertex("One") |
| 180 | + g1.insertVertex("Two") |
| 181 | + g1.insertVertex("Three") |
| 182 | + |
| 183 | + g1.insertEdge("Zero", "One") |
| 184 | + g1.insertEdge("Zero", "Three") |
| 185 | + g1.insertEdge("One", "Two") |
| 186 | + g1.insertEdge("Two", "One") |
| 187 | + g1.insertEdge("Three", "Zero") |
| 188 | + g1.insertEdge("Three", "Two") |
| 189 | + |
| 190 | + g1.warshalls() |
| 191 | + |
| 192 | + |
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