10/23

Author: anubhav1006

src/DSA/Graphs/AlienDictionaryTry.java

@@ -0,0 +1,74 @@
+package DSA.Graphs;
+
+import java.util.*;
+
+public class AlienDictionaryTry {
+
+
+ static class Graph{
+ int v;
+ LinkedList<Character>[] adjList;
+ boolean[] visited;
+
+ public Graph(int v) {
+ this.v = v;
+ adjList = new LinkedList[v];
+ visited = new boolean[v];
+ for (int i=0;i<v;i++){
+ adjList[i] = new LinkedList<>();
+ }
+ }
+
+ void addEdge(int src, char dest){
+ adjList[src].add(dest);
+
+ }
+ }
+
+ public static void main(String[] args) {
+ String[] words = {"caa", "aaa", "aab"};
+ int noOfAlphabets = 3;
+ printOrder(words, noOfAlphabets);
+ }
+ static Stack<Character> st = new Stack<>();
+
+ private static void printOrder(String[] words, int count) {
+ int n = words.length;
+ Graph g = new Graph(count);
+ for(int i=0;i<n-1;i++){
+ String a = words[i];
+ String b = words[i+1];
+
+ int j = (a.length()>b.length())? b.length():a.length();
+ while(j>0){
+ if(a.charAt(j-1)!=b.charAt(j-1)){
+ g.addEdge(a.charAt(j-1)-97, b.charAt(j-1));
+ break;
+ }
+ j--;
+ }
+ }
+ for(int i=0;i<count;i++){
+ if(!g.visited[i])
+ topoSort(g,i);
+ }
+
+ while (!st.empty()){
+ System.out.print(st.pop()+" ");
+ }
+ }
+
+ private static void topoSort(Graph g,int src) {
+
+ g.visited[src] = true;
+ Iterator<Character> it = g.adjList[src].listIterator();
+ char c;
+ while(it.hasNext()){
+ c = it.next();
+ if(!g.visited[c-97]){
+ topoSort(g,c-97);
+ }
+ }
+ st.push((char)(src+'a'));
+ }
+}

src/DSA/Graphs/MST/Prim.java

@@ -40,7 +40,6 @@ public void primMST(int[][] graph) {
  //Start of graph
  keySet[0]=0;
  minSpanSet[0]= -1;
- int counter =0;
  for(int i=0;i<v-1;i++) {
  int min_key = findMinKey(keySet,spanned);
  spanned[min_key] = true;

src/DSA/Trees/ConnectNodesSameLevel.java

@@ -0,0 +1,60 @@
+package DSA.Trees;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class ConnectNodesSameLevel {
+
+ static class Node{
+ int data;
+ Node left, right, nextRight;
+
+ public Node(int key) {
+ this.data = key;
+ left = right = nextRight = null;
+ }
+ }
+
+ public static void main(String[] args) {
+ Node root = new Node(10);
+ root.left = new Node(8);
+ root.right = new Node(2);
+ root.left.left = new Node(3);
+ root.right.right = new Node(90);
+
+ // Populates nextRight pointer in all nodes
+ connect(root);
+
+ // Let us check the values of nextRight pointers
+ System.out.println("Following are populated nextRight pointers in \n" +
+ "the tree (-1 is printed if there is no nextRight)");
+ System.out.println("nextRight of "+ root.data +" is "+
+ ((root.nextRight != null) ? root.nextRight.data : -1));
+ System.out.println("nextRight of "+ root.left.data+" is "+
+ ((root.left.nextRight != null) ? root.left.nextRight.data : -1));
+ System.out.println("nextRight of "+ root.right.data+" is "+
+ ((root.right.nextRight != null) ? root.right.nextRight.data : -1));
+ System.out.println("nextRight of "+ root.left.left.data+" is "+
+ ((root.left.left.nextRight != null) ? root.left.left.nextRight.data : -1));
+ System.out.println("nextRight of "+ root.right.right.data+" is "+
+ ((root.right.right.nextRight != null) ? root.right.right.nextRight.data : -1));
+ }
+
+ private static void connect(Node root) {
+ Queue<Node> q = new LinkedList<>();
+ q.add(root);
+ q.add(null);
+ while(!q.isEmpty()){
+ Node temp = q.poll();
+ if(temp!=null) {
+ temp.nextRight = q.peek();
+ if (temp.left != null)
+ q.add(temp.left);
+ if (temp.right != null)
+ q.add(temp.right);
+ }
+ else if(!q.isEmpty())
+ q.add(null);
+ }
+ }
+}