Merge branch 'smv1999:master' into manny

Author: MannyP31

DSA 450 GFG/next_permutation.py

@@ -0,0 +1,34 @@
+# Link for the problem : https://leetcode.com/problems/next-permutation/
+
+
+class Solution(object):
+    
+    def nextPermutation(self, nums):
+      found = False
+      i = len(nums)-2
+      while i >=0:
+         if nums[i] < nums[i+1]:
+            found =True
+            break
+         i-=1
+      if not found:
+         nums.sort()
+      else:
+         m = self.findMaxIndex(i+1,nums,nums[i])
+         nums[i],nums[m] = nums[m],nums[i]
+         nums[i+1:] = nums[i+1:][::-1]
+      return nums
+  
+    def findMaxIndex(self,index,a,curr):
+      ans = -1
+      index = 0
+      for i in range(index,len(a)):
+         if a[i]>curr:
+            if ans == -1:
+               ans = curr
+               index = i
+            else:
+               ans = min(ans,a[i])
+               index = i
+      return index
+ob1 = Solution()

Data Structures/Linked Lists/Doubly Linked List/delete_at_begin.cpp

@@ -0,0 +1,107 @@
+/*
+
+This is a Doubly Linked List program which deletes a node at the beginning to the Linked List.
+Since, it is a Doubly Linked List, both the forward and backward traversal is also possible.
+
+*/
+
+#include <iostream>
+
+using namespace std;
+
+/*
+
+Node definition:
+	1. Pointer to previous node.
+	2. Integer Data
+	3. Pointer to next node.
+
+*/
+
+class dll_node {
+public:
+	dll_node* prev;
+	int data;
+	dll_node* next;
+};
+
+void createDLL(dll_node* &head) {
+
+	int choice;
+
+	dll_node* temp = head;
+
+	do {
+
+		int data;
+
+		cout << "Enter Data : ";
+		cin >> data;
+
+		dll_node* newNode = new dll_node();
+		newNode->data = data;
+		newNode->prev = NULL;
+		newNode->next = NULL;
+
+		if(head == NULL) {
+			head = newNode;
+			temp = head;
+		} else {
+			temp->next = newNode;
+			newNode->prev = temp;
+			temp = newNode;
+		}
+
+		cout << "Do you want to continue? (1/0) : ";
+		cin >> choice;
+
+	} while(choice == 1);
+
+
+}
+
+void delete_at_begin(dll_node* &head) {
+
+	if(head == NULL)
+		return;
+
+	if(head->next == NULL) {
+		dll_node* temp = head;
+		head = head->next;
+		delete temp;
+		return;
+	}
+
+	dll_node* temp = head;
+	head = head->next;
+	head->prev = NULL;
+	delete temp;
+	return;
+
+}
+
+void display(dll_node* head) {
+	cout << "The elements are : ";
+	while(head != NULL) {
+		cout << head->data << " ";
+		head = head->next;
+	}
+	cout << endl;
+}
+
+int main() {
+
+	dll_node* head = NULL;
+
+	createDLL(head);
+
+	cout << "Before Deletion : " << endl;
+	display(head);
+
+	delete_at_begin(head);
+
+	cout << "After Deletion : " << endl;
+	display(head);
+
+	return 0;
+}

Data Structures/Linked Lists/Doubly Linked List/delete_at_end.cpp

@@ -0,0 +1,103 @@
+/*
+
+This is a Doubly Linked List program which deletes a node at the end to the Linked List.
+Since, it is a Doubly Linked List, both the forward and backward traversal is also possible.
+
+*/
+
+#include <iostream>
+
+using namespace std;
+
+/*
+
+Node definition:
+	1. Pointer to previous node.
+	2. Integer Data
+	3. Pointer to next node.
+
+*/
+
+class dll_node {
+public:
+	dll_node* prev;
+	int data;
+	dll_node* next;
+};
+
+void createDLL(dll_node* &head) {
+
+	int choice;
+
+	dll_node* temp = head;
+
+	do {
+
+		int data;
+
+		cout << "Enter Data : ";
+		cin >> data;
+
+		dll_node* newNode = new dll_node();
+		newNode->data = data;
+		newNode->prev = NULL;
+		newNode->next = NULL;
+
+		if(head == NULL) {
+			head = newNode;
+			temp = head;
+		} else {
+			temp->next = newNode;
+			newNode->prev = temp;
+			temp = newNode;
+		}
+
+		cout << "Do you want to continue? (1/0) : ";
+		cin >> choice;
+
+	} while(choice == 1);
+
+
+}
+
+void delete_at_end(dll_node* &head) {
+	
+	if(head == NULL)
+		return;
+
+	dll_node* temp = head;
+	while(temp->next != NULL) {
+		temp = temp->next;
+	}
+
+	temp->prev->next = NULL;
+	delete temp;
+	return;
+
+}
+
+void display(dll_node* head) {
+	cout << "The elements are : ";
+	while(head != NULL) {
+		cout << head->data << " ";
+		head = head->next;
+	}
+	cout << endl;
+}
+
+int main() {
+
+	dll_node* head = NULL;
+
+	createDLL(head);
+
+	cout << "Before Deletion : " << endl;
+	display(head);
+
+	delete_at_end(head);
+
+	cout << "After Deletion : " << endl;
+	display(head);
+
+	return 0;
+}

Data Structures/Linked Lists/Doubly Linked List/insert_at_begin.cpp

@@ -0,0 +1,80 @@
+/*
+
+This is a Doubly Linked List program which gets a integer data from the user and
+creates a node which is inserted at the beginning to the Linked List.
+
+Since, it is a Doubly Linked List, both the forward and backward traversal is also possible.
+
+
+*/
+
+#include <iostream>
+
+using namespace std;
+
+/*
+
+Node definition:
+	1. Pointer to previous node.
+	2. Integer Data
+	3. Pointer to next node.
+
+*/
+
+class dll_node {
+public:
+	dll_node* prev;
+	int data;
+	dll_node* next;
+};
+
+void createDLL(dll_node* &head) {
+
+	int choice;
+
+	do {
+
+		int data;
+
+		cout << "Enter Data : ";
+		cin >> data;
+
+		dll_node* newNode = new dll_node();
+		newNode->data = data;
+		newNode->prev = NULL;
+		newNode->next = NULL;
+
+		if(head == NULL) {
+			head = newNode;
+		} else {
+			newNode->next = head;
+			head->prev = newNode;
+			head = newNode;
+		}
+
+		cout << "Do you want to continue? (1/0) : ";
+		cin >> choice;
+
+	} while(choice == 1);
+
+
+}
+
+void display(dll_node* head) {
+	cout << "The elements are : ";
+	while(head != NULL) {
+		cout << head->data << " ";
+		head = head->next;
+	}
+	cout << endl;
+}
+
+int main() {
+
+	dll_node* head = NULL;
+
+	createDLL(head);
+	display(head);
+
+	return 0;
+}