Example 1: DFS in c++
#include
using namespace std;
class Graph {
int V;
list* adj;
void DFSUtil(int v, bool visited[]);
public:
Graph(int V);
void addEdge(int v, int w);
void DFS(int v);
};
Graph::Graph(int V)
{
this->V = V;
adj = new list[V];
}
void Graph::addEdge(int v, int w)
{
adj[v].push_back(w);
}
void Graph::DFSUtil(int v, bool visited[])
{
visited[v] = true;
cout << v << " ";
list::iterator i;
for (i = adj[v].begin(); i != adj[v].end(); ++i)
if (!visited[*i])
DFSUtil(*i, visited);
}
void Graph::DFS(int v)
{
bool* visited = new bool[V];
for (int i = 0; i < V; i++)
visited[i] = false;
DFSUtil(v, visited);
}
int main()
{
Graph g(4);
g.addEdge(0, 1);
g.addEdge(0, 2);
g.addEdge(1, 2);
g.addEdge(2, 0);
g.addEdge(2, 3);
g.addEdge(3, 3);
cout << "Following is Depth First Traversal"
" (starting from vertex 2) \n";
g.DFS(2);
return 0;
}
Example 2: depth first search
# HAVE USED ADJACENY LIST
class Graph:
def __init__(self,lst=None):
self.lst=dict()
if lst is None:
pass
else:
self.lst=lst
def find_path(self,start,end):
self.checklist={}
for i in self.lst.keys():
self.checklist[i]=False
self.checklist[start]=True
store,extra=(self.explore(start,end))
if store==False:
print('No Path Found')
else:
print(extra)
def explore(self,start,end):
while True:
q=[]
#print(self.checklist,q)
q.append(start)
flag=False
for i in self.lst[start]:
if i==end:
q.append(i)
return True,q
if self.checklist[i]:
pass
else:
flag=True
self.checklist[i]=True
q.append(i)
break
if flag:
store,extra=self.explore(q[-1],end)
if store==False:
q.pop()
if len(q)==0:return False
return self.explore(q[-1],end)
elif store==None:
pass
elif store==True:
q.pop()
q.extend(extra)
return True,q
else:
return False,None
def __str__(self):return str(self.lst)
if __name__=='__main__':
store={1: [2, 3, 4], 2: [3, 1], 3: [2, 1], 4: [5, 8, 1], 5: [4, 6, 7], 6: [5, 7, 9, 8], 7: [5, 6], 8: [4, 6, 9], 9: [6, 8, 10], 10: [9],11:[12,13]}
a=Graph(store)
a.find_path(1,11) # No Path Found
a.find_path(1,6)# [1, 4, 5, 6]
a.find_path(3,10) # [3, 2, 1, 4, 5, 6, 9, 10]
a.find_path(4,10)# [4, 5, 6, 9, 10]
print(a) #