76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
/**
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* File: graph_dfs.c
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* Created Time: 2023-07-13
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* Author: NI-SW (947743645@qq.com)
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*/
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#include "graph_adjacency_list.c"
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// Assume maximum number of nodes is 100
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#define MAX_SIZE 100
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/* Check if vertex has been visited */
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int isVisited(Vertex **res, int size, Vertex *vet) {
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// Traversal search node, using O(n) time
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for (int i = 0; i < size; i++) {
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if (res[i] == vet) {
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return 1;
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}
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}
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return 0;
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}
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/* Depth-first traversal helper function */
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void dfs(GraphAdjList *graph, Vertex **res, int *resSize, Vertex *vet) {
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// Record visited vertex
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res[(*resSize)++] = vet;
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// Traverse all adjacent vertices of that vertex
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AdjListNode *node = findNode(graph, vet);
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while (node != NULL) {
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// Skip already visited vertices
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if (!isVisited(res, *resSize, node->vertex)) {
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// Recursively visit adjacent vertices
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dfs(graph, res, resSize, node->vertex);
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}
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node = node->next;
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}
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}
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/* Depth-first traversal */
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// Use adjacency list to represent the graph, to obtain all adjacent vertices of a specified vertex
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void graphDFS(GraphAdjList *graph, Vertex *startVet, Vertex **res, int *resSize) {
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dfs(graph, res, resSize, startVet);
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}
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/* Driver Code */
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int main() {
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// Initialize undirected graph
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int vals[] = {0, 1, 2, 3, 4, 5, 6};
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int size = sizeof(vals) / sizeof(vals[0]);
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Vertex **v = valsToVets(vals, size);
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Vertex *edges[][2] = {{v[0], v[1]}, {v[0], v[3]}, {v[1], v[2]}, {v[2], v[5]}, {v[4], v[5]}, {v[5], v[6]}};
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int egdeSize = sizeof(edges) / sizeof(edges[0]);
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GraphAdjList *graph = newGraphAdjList();
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// Add all vertices and edges
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for (int i = 0; i < size; i++) {
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addVertex(graph, v[i]);
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}
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for (int i = 0; i < egdeSize; i++) {
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addEdge(graph, edges[i][0], edges[i][1]);
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}
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printf("\nAfter initialization, the graph is\n");
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printGraph(graph);
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// Depth-first traversal
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Vertex *res[MAX_SIZE];
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int resSize = 0;
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graphDFS(graph, v[0], res, &resSize);
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printf("\nDepth-first search (DFS) vertex sequence is\n");
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printArray(vetsToVals(res, resSize), resSize);
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// Free memory
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delGraphAdjList(graph);
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free(v);
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return 0;
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}
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