Added Important Algos

DataStructures/HashMap/Hashing/Intersection

@@ -0,0 +1,37 @@
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.Set;
+
+public class Intersection {
+
+	public static ArrayList Main(int arr[],int arr2[]) {
+		HashMap<Integer,Integer> hmap=new HashMap<>();
+		HashMap<Integer,Integer> hmap2=new HashMap<>();
+		for(int i=0;i<arr.length;i++) {
+			if(hmap.containsKey(arr[i])) {
+				int val=hmap.get(arr[i]);
+				hmap.put(arr[i],val+1);
+			}else
+				hmap.put(arr[i],1);
+
+		}
+		ArrayList<Integer> res=new ArrayList<>();
+		for(int i=0;i<arr2.length;i++) {
+			if(hmap.containsKey(arr2[i])&&hmap.get(arr2[i])>0) {
+				int val=hmap.get(arr2[i]);
+				hmap.put(arr2[i],val-1);
+				res.add(arr2[i]);
+			}
+
+		}
+		return res;
+	}
+	public Intersection() {
+
+	}
+
+
+
+}

DataStructures/Lists/ListAddnFun

@@ -0,0 +1,100 @@
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+class LinkedList {
+	    private class Node{    
+	        int data;    
+	        Node next;    
+
+	        Node(int data) {    
+	            this.data = data;    
+	            this.next = null;    
+	        }    
+	    }
+	    public Node head = null;    
+	    public Node tail = null;    
+	    private int size=0;    
+
+	    public void addLast(int data) {    
+	        Node newNode = new Node(data);    
+
+	        if(this.head == null) {    
+	            this.head = newNode;    
+	            this.tail = newNode;  
+	            this.size++;
+	        }    
+	        else {    
+	            this.tail.next = newNode;    
+	            this.tail = newNode;    
+	            this.size++;
+	        }    
+	    }    
+
+
+	    public void display() {    
+	        Node current = this.head;    
+	        if(this.head == null) {    
+	            return;    
+	        }    
+	        while(current != null) {    
+	            System.out.print(current.data + " ");    
+	            current = current.next;    
+	        }    
+	        System.out.println();    
+	    }    
+
+	    public void formLL2(LinkedList LL1) {
+	    	Node current=LL1.head;
+	    	while(current.next!=null&&current.next.next!=null) {
+	    		int sum=current.data+current.next.next.data;
+	    		this.addLast(sum);
+	    		current=current.next.next;
+	    	}	
+	    }
+	    public void formLL3(LinkedList LL1) {
+	    	Node current=LL1.head.next;
+	    	while(current.next!=null&&current.next.next!=null) {
+	    		int sum=current.data+current.next.next.data;
+	    		this.addLast(sum);
+	    		current=current.next.next;	    		
+	    	}	
+	    }
+	    public Node mid() {
+	    	Node slow=this.head;
+	    	Node fast=this.head;
+	    	while(fast.next!=null && fast.next.next!=null) {
+	    		slow=slow.next;
+	    		fast=fast.next.next;
+	    	}
+	    	return slow;
+	    }
+	    public Node midValue() {
+	    	int sum=this.head.data+this.tail.data;
+	    	Node mid=new Node(sum);
+	    	return mid;
+	    }
+	    public void formRes(LinkedList LL1,LinkedList LL2,LinkedList LL3,Node MID) {
+	    	Node LL1mid=LL1.mid();
+	    	Node currentLL1=LL1.head;
+	    	Node currentLL2=LL2.head;
+	    	Node currentLL3=LL3.head;
+	    	while(currentLL1!=null) {
+    			this.addLast(currentLL1.data);
+
+	    		if(currentLL2!=null) {
+	    			this.addLast(currentLL2.data);
+	    			currentLL2=currentLL2.next;
+	    		}else if(currentLL1.equals(LL1mid)) {
+	    			this.addLast(MID.data);
+	    		}
+	    		else if(currentLL2==null&&currentLL3!=null) {
+	    			this.addLast(currentLL3.data);
+	    			currentLL3=currentLL3.next;
+	    		}
+    			currentLL1=currentLL1.next;	
+	    	}
+	    }
+	    public void Size() {
+	    	System.out.println(this.size);
+	    }
+  }

DataStructures/Trees/AVLSimple

@@ -0,0 +1,106 @@
+public class AVLTree {
+	private class Node{
+		int data;
+		int height;
+		Node left;
+		Node right;
+		Node(int data){
+			this.data=data;
+			this.height=1;
+		}
+
+	}
+	private Node root;
+	public void insert(int data) {
+		this.root=insert(this.root,data);
+	}
+	private Node insert(Node node,int item) {
+		if(node==null) {
+			Node add=new Node(item);
+			return add;
+		}
+		if(node.data>item) {
+			node.left=insert(node.left,item);
+		}
+		if(node.data<item) {
+			node.right=insert(node.right,item);
+		}
+		node.height=Math.max(height(node.left),height(node.right))+1;
+		int bf=bf(node);
+		//LL case
+		if(bf>1&&item<node.left.data)
+			return rightRotate(node);
+		//RR case
+		if(bf<-1&&item>node.right.data)
+			return leftRotate(node);
+		//RL case
+		if(bf<-1&&item<node.right.data) {
+			node.right=rightRotate(node.right);
+			return leftRotate(node);
+		}
+		//LR case
+		if(bf>1&&item>node.left.data) {
+			node.left=leftRotate(node.left);
+			return rightRotate(node);
+		}
+
+		return node;
+	}
+	public void display() { 
+		this.display(this.root);
+		System.out.println(this.root.height);
+	}
+	private void display (Node node) {
+		String str="";
+		if(node.left!=null)
+			str+=node.left.data+"=>";
+		else
+			str+="END=>";
+		str+=node.data+"";
+		if(node.right!=null)
+			str+="<="+node.right.data;
+		else
+			str+="<=END";
+		System.out.println(str);
+		if(node.left!=null)
+			display(node.left);
+		if(node.right!=null)
+			display(node.right);
+	}
+	private int height(Node node) {
+		if(node==null) {
+			return 0;
+		}
+		return node.height;
+
+	}
+	private int bf(Node node) {
+		if(node==null)
+			return 0;
+		return height(node.left)-height(node.right);
+	}
+
+	private Node rightRotate(Node c) {
+		Node b=c.left;
+		Node T3=b.right;
+
+		b.right=c;
+		c.left=T3;
+		c.height=Math.max(height(c.left),height(c.right))+1;
+		b.height=Math.max(height(b.left),height(b.right))+1;
+		return b;
+
+	}
+	private Node leftRotate(Node c) {
+		Node b=c.right;
+		Node T3=b.left;
+
+		b.left=c;
+		c.right=T3;
+		c.height=Math.max(height(c.left),height(c.right))+1;
+		b.height=Math.max(height(b.left),height(b.right))+1;
+		return b;
+
+	}
+
+}

DynamicProgramming/BoardPath

@@ -0,0 +1,52 @@
+
+public class BoardPath {
+	public static long startTime;
+	public static long endTime;
+	public static void startAlgo() {
+		startTime=System.currentTimeMillis();
+	}
+	public static long endAlgo() {
+		endTime=System.currentTimeMillis();
+		return endTime-startTime;
+	}
+	public static int bpR(int start,int end){
+		if(start==end) {
+			return 1;
+		}
+		else if(start>end)
+			return 0;
+		int count=0;
+		for(int dice=1;dice<=6;dice++) {
+			count+=bpR(start+dice,end);
+		}
+		return count;
+	}
+	public static int bpRS(int curr,int end,int strg[]){
+		if(curr==end) {
+			return 1;
+		}
+		else if(curr>end)
+			return 0;
+		if(strg[curr]!=0)
+			return strg[curr];
+		int count=0;
+		for(int dice=1;dice<=6;dice++) {
+			count+=bpRS(curr+dice,end,strg);
+		}
+		strg[curr]=count;
+		return count;
+	}
+	public static int bpIS(int curr,int end,int[]strg){
+		strg[end]=1;
+		for(int i=end-1;i>=0;i--) {
+			int count=0;
+			for(int dice=1;dice<=6&&dice+i<strg.length;dice++) {
+				count+=strg[i+dice];
+			}
+			strg[i]=count;
+		}
+		return strg[0];
+	}
+
+
+}