1. Instructor : Prof. Jyh-Shing Roger Jang
Depth First Search
Instructor : Prof. Jyh-Shing Roger Jang
Designer：Shao-Huan Wang
The ideas are reference to the textbook “Fundamentals of Data Structures in C “ .

2. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ 1 node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 1 1 1 1 2 1 1 1 3 4 5 6 1
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v
Find the node which is not visited

3. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 2 2 2 1 2 2 2 2 3 4 5 6 1 2
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1
Find the node which is not visited

4. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 3 3 3 1
visited 2 3 3 3 3 4 5 6 1 2 3
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1 3
Find the node which is not visited

5. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 4 4 4 1 2 4 4 4 3
visited 4 5 6 1 2 3 4
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1 3 7
Find the node which is not visited

6. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 5 5 5 1 2
visited 5 5 5 3 4 5 6 1 2 3 4
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
visited
Markup the node which already visited
Print the value of v 1 3 7 4
Find the node which is not visited

7. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 1 2 4 4 3 4 5 6 1 2 3 4
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1 3 7 4
Find the node which is not visited

8. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 5 5 5 1 2 5 5 5 3 4 5 6 1 2 3 4 5
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1 3 7 4 5
Find the node which is not visited

9. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); }
visited 6 6 6 1 2 6 6 6 3 4 5 6
visited 1 2 3 4 5 6
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1 3 7 4 5 2
Find the node which is not visited

10. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 7 7 7 1 2
visited 7 7 7 3 4 5 6
visited 1 2 3 4 5 6
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
visited
Markup the node which already visited
Print the value of v 1 3 7 4 5 2 6
Find the node which is not visited

11. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 1 2 5 4 6 4 5 3 4 5 6
visited 1 2 3 4 5 6
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
visited
Markup the node which already visited
Print the value of v 1 3 7 4 5 2 6
Find the node which is not visited

12. Depth First Search 1 2 3 4 5 6 7 void dfs(int v){ node_pointer w;
void dfs(int v){
node_pointer w;
visited[v] = TURE;
printf(“%5d”, v);
for(w = graph[v]; w; w = w->link)
if(!visited[w->vertex])
dfs(w->vertex); } 1 2
visited 1 3 2 2 1 3 4 5 6
visited 1 2 3
Input the first vertex into dfs 7
Declare variable to put the graph[v] of Adj-list
Markup the node which already visited
Print the value of v 1 3 7 4 5 2 6
Find the node which is not visited