CHAPTER 25 Weighted Graphs and Applications Objectives • To ...

131 for (int i = 0; i < getSize(); i++)
132 {
133 if (find(T.begin(), T.end(), i)== T.end()
134 && cost[i] < currentMinCost)
135 {
136 currentMinCost = cost[i];
137 u = i;
138 }
139 }
140
141 T.push_back(u); // Add a new vertex to T
142 totalWeight += cost[u]; // Add cost[u] to the tree
143
144 // Adjust cost[v] for v that is adjacent to u and v in V - T
145 for (Edge* e: neighbors[u])
146 {
147 if (find(T.begin(), T.end(), e->v) == T.end()
148 && cost[e->v] > static_cast(e)->weight)
149 {
150 cost[e->v] = static_cast(e)->weight;
151 parent[e->v] = u;
152 }
153 }
154 } // End of while
155
156 return MST(startingVertex, parent, T, totalWeight);
157 }
158
159 template
160 ShortestPathTree WeightedGraph::getShortestPath(int
sourceVertex)
161 {
162 // T stores the vertices whose path found so far
163 vector T;
164
165 // parent[v] stores the previous vertex of v in the path
166 vector parent(getSize());
167 parent[sourceVertex] = -1; // The parent of source is set to -1
168
169 // cost[v] stores the cost of the path from v to the source
170 vector cost(getSize());
171 for (unsigned i = 0; i < cost.size(); i++)
172 {
173 cost[i] = INFINITY; // Initial cost set to infinity
174 }
175 cost[sourceVertex] = 0; // Cost of source is 0
176
177 // Expand T
178 while (T.size() < getSize())
179 {
180 // Find smallest cost v in V - T
181 int u = -1; // Vertex to be determined
182 double currentMinCost = INFINITY;
183 for (int i = 0; i < getSize(); i++)
184 {
185 if (find(T.begin(), T.end(), i)== T.end()
186 && cost[i] < currentMinCost)
187 {
188 currentMinCost = cost[i];
10