From d2372945859a0ce02e17a6e9928bde998af16297 Mon Sep 17 00:00:00 2001
From: NasreenParween <nasreen999786@gmail.com>
Date: Thu, 7 Jul 2022 17:49:05 +0530
Subject: [PATCH] Depth-First Search

---
 DAA_DFS.cpp | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 DAA_DFS.cpp

diff --git a/DAA_DFS.cpp b/DAA_DFS.cpp
new file mode 100644
index 0000000..cd21197
--- /dev/null
+++ b/DAA_DFS.cpp
@@ -0,0 +1,109 @@
+#include <iostream>
+#include<stdlib.h>
+using namespace std;
+#define MAX 30
+template<class t>
+class node
+{
+	public:
+	node *next;
+	int vertex;
+};
+template<class t>
+class graphq
+{
+	public:
+	int data[MAX];
+	int rear,front;
+	void DFS(int);
+	void readgraph();
+	int empty(graphq *);
+	int full(graphq *);
+	void insert(int vi, int vj);
+	int discovered[MAX];
+	int layer[MAX],parent[MAX];
+	node<t> *heads[MAX];
+	int n;
+};
+
+
+template<class t>
+void graphq<t>::DFS(int i)
+{
+	node<t> *p;
+	cout<<"\t"<<i;
+	p=heads[i];
+	discovered[i]=1;
+	while(p!=NULL)
+	{
+		i=p->vertex;
+		if(!discovered[i])
+		{
+			DFS(i);
+		}
+		p=p->next;
+	}
+}
+template<class t>
+int graphq<t>::empty(graphq *p)
+{
+	if(p->rear==-1)
+	return(1);
+	return(0);
+
+}
+template<class t>
+int graphq<t>::full(graphq *p)
+{
+	if(p->rear==MAX-1)
+	return(1);
+	return(0);
+}
+template<class t>
+void graphq<t>::readgraph()
+{
+	int i,vi,vj, nofedges;
+	cout<<"\nEnter the number of vertices : ";
+	cin>>n;
+	for(i=0;i<n;i++)
+	heads[i]=NULL;
+	cout<<"\nEnter the number of edges : ";
+	cin>>nofedges;
+	for(i=0;i<nofedges;i++)
+	{
+		cout<<"\nEnter an edge (u,v) : ";
+		cin>>vi>>vj;
+		insert(vi,vj);
+		insert(vj,vi);
+	}
+}
+template<class t>
+void graphq<t>::insert(int vi, int vj)
+{
+	node<t>*P;
+	node<t>*Q;
+	Q=new node<t>;
+	Q->vertex=vj;
+	Q->next=NULL;
+	if(heads[vi]==NULL)
+	heads[vi]=Q;
+	else
+	{
+		P=heads[vi];
+		while(P->next!=NULL)
+		P=P->next;
+		P->next=Q;
+	}
+}
+int main()
+{
+	int i;
+	graphq<int>gq;
+	cout<<"\nCreate a node : ";
+	gq.readgraph();
+	cout<<"\nDFS";
+	cout<<"\nStarting node number : ";
+	cin>>i;
+	gq.DFS(i);
+	return 0;
+}