inserted on more node

linked_list_problems/deleteNode.cpp

@@ -7,7 +7,7 @@ struct Node {
   int data;
   Node * next;
   Node( int d ) : data{ d }, next{ nullptr } { }
-};
+}*head=NULL;
 
 void insert( Node * & head, int data )
 {
@@ -32,17 +32,26 @@ void printList( Node * head )
   std::cout << "NULL" << std::endl;
 }
 
-void deleteNode( Node * node )
+void deleteNode( Node * node ) // works in every condition
 {
-  // return if node is null
-  if ( node == nullptr ) {
-    return;
+  Node *p=head;
+  Node *q=NULL;
+  while(p!=node)
+  {
+      q=p;
+      p=p->next;
   }
+  q->next=p->next;
+  p->next=NULL;
+  delete p;
+
+
+
+
 
-  //this method won't work if we are given last node
-  if ( node->next == nullptr ) {
-    return;
-  }
+
+
+}
 
   Node * nextNode = node->next;
   node->data = nextNode->data;
@@ -52,12 +61,13 @@ void deleteNode( Node * node )
 
 int main()
 {
-  Node * head = nullptr;
+
   insert( head, 1 );
   insert( head, 12 );
   insert( head, 2 );
   insert( head, 3 );
   insert( head, 4 );
+    insert( head, 5 );
   printList( head );
   std::cout << "Deleting node with data 12 \n";
   deleteNode( head->next );

linked_list_problems/reverseLinkedListIterAndRecurse.cpp

@@ -4,7 +4,7 @@ struct Node {
   int data;
   Node * next;
   Node( int d ) : data{ d }, next{ nullptr } { }
-};
+}*head=NULL;
 
 void push( Node * & head, int data ) {
   Node *newNode = new Node(data);
@@ -48,16 +48,18 @@ void reverseRecur( Node * & head ) {
   if ( head == nullptr || ( head != nullptr && head->next == nullptr ) ) {
     return;
   }
-  Node * first = head;
-  Node * rest = head->next;
-  reverseRecur( rest );
-  first->next->next = first;
-  first->next = nullptr;
-  head = rest;
+  else
+  {
+  std :: cout<<head->data;
+  reverseRecur(head->next);
+  }
 }
 
+
+
+
 int main() {
-  Node *head = nullptr;
+
   push( head, 1 );
   push( head, 2 );
   push( head, 3 );

sort_search_problems/findMaximum.cpp

@@ -1,4 +1,4 @@
-/**
+/** this is valid on both increasing or decreasing
  * Find the maximum element in an array which is first increasing and then decreasing.
  * Input: arr[] = {8, 10, 20, 80, 100, 200, 400, 500, 3, 2, 1}
  * Output: 500