Depth-first traversal of undirected graphs in Data Structures

The following figure is an example. Only the source code is provided, regardless of the algorithm concept.

# Include <stdio. h> # include <cstring> # include <iostream> # define max_vertex_num 20 + 3 // maximum number of vertices // # define true 1 // # define false 0 using namespace STD; typedef char vertex_type; // vertex type typedef struct node {int vertex_num; // Number of vertices int edge_num; // Number of edges vertex_type vertex [max_vertex_num]; // vertex information int matrix [max_vertex_num] [max_vertex_num]; // bool visited [max_vertex_num]; // undigraph for Deep Search}; // undirected graph void init _ Undigraph (undigraph * g) // initialization graph {G-> vertex_num = G-> edge_num = 0; memset (G-> vertex, 0, sizeof (G-> vertex); memset (G-> matrix, 0, sizeof (G-> matrix); memset (G-> visited, 0, sizeof (G-> visited); // It should be used to initialize the logical array} void add_vertex (undigraph * g) // Add the vertex {printf ("Enter the number of vertices \ n"); CIN> G-> vertex_num; // scanf ("% d ", & G-> vertex_num); For (INT I = 0; I <G-> vertex_num; ++ I) CIN> G-> vertex [I]; // scanf ("% C", & G-> vertex [I]);} int loca Te_vertex (undigraph * g, vertex_type who) // locate a vertex {for (INT Index = 0; index <G-> vertex_num; ++ index) if (G-> vertex [Index] = who) Return Index; // return cannot find return-1; // Meaning} void add_edge (undigraph * g) // Add edge {printf ("Enter the number of edge \ n"); CIN> G-> edge_num; // scanf ("% d ", & G-> edge_num); For (INT I = 0; I <G-> edge_num; ++ I) {vertex_type S1, S2; // The vertex CIN> S1> S2 at both ends of the edge; // scanf ("% C", & S1, & S2); int index_1 = loca Te_vertex (G, S1); // locate the subscript int index_2 = locate_vertex (G, S2) where the two vertices are located ); // same as G-> matrix [index_1] [index_2] = G-> matrix [index_2] [index_1] = 1; // The matrix is symmetric} void create_undigraph (undigraph * g) // constructs an undirected graph {add_vertex (g); // adds the vertex add_edge (g ); // Add edge} void DFS (undigraph * g, int I) {cout <G-> vertex [I]; // printf ("% C ", & G-> vertex [I]); G-> visited [I] = true; For (Int J = 0; j <G-> vertex_num; ++ J) if (G-> matrix [I] [J] = 1 &&! G-> visited [J]) DFS (G, J);} void dfs_traverse (undigraph * g) {for (INT I = 0; I <G-> vertex_num; ++ I) if (! G-> visited [I]) DFS (G, I);} int main (void) {undigraph g; init_undigraph (& G ); // initialize undirected graph create_undigraph (& G); // construct an undirected graph dfs_traverse (& G); // returns 0 for depth-first traversal ;}

Depth-first traversal of undirected graphs in Data Structures