Added codes for 1 April

GeeksForGeeks/April/01-4-24/GFG.java

@@ -0,0 +1,193 @@
+//{ Driver Code Starts
+import java.io.*;
+import java.util.*;
+
+class Node {
+    int data;
+    Node left;
+    Node right;
+
+    Node(int data) {
+        this.data = data;
+        left = null;
+        right = null;
+    }
+
+    public static Node buildTree(String str) {
+        // Corner Case
+        if (str.length() == 0 || str.charAt(0) == 'N') return null;
+
+        // Creating array of Strings from input
+        // String after spliting by space
+        String ip[] = str.split(" ");
+
+        // Create the root of the tree
+        Node root = new Node(Integer.parseInt(ip[0]));
+
+        // Push the root to the queue
+        Queue<Node> queue = new LinkedList<>();
+        queue.add(root);
+
+        // Starting from the second element
+        int i = 1;
+        while (queue.size() > 0 && i < ip.length) {
+
+            // Get and remove the front of the queue
+            Node currNode = queue.peek();
+            queue.remove();
+
+            // Get the current node's value from the string
+            String currVal = ip[i];
+
+            // If the left child is not null
+            if (!currVal.equals("N")) {
+
+                // Create the left child for the current node
+                currNode.left = new Node(Integer.parseInt(currVal));
+                // Push it to the queue
+                queue.add(currNode.left);
+            }
+
+            // For the right child
+            i++;
+            if (i >= ip.length) break;
+
+            currVal = ip[i];
+
+            // If the right child is not null
+            if (!currVal.equals("N")) {
+
+                // Create the right child for the current node
+                currNode.right = new Node(Integer.parseInt(currVal));
+
+                // Push it to the queue
+                queue.add(currNode.right);
+            }
+            i++;
+        }
+
+        return root;
+    }
+
+    public static Node inputTree(BufferedReader br) throws IOException {
+        return buildTree(br.readLine().trim());
+    }
+
+    public static void inorder(Node root) {
+        if (root == null) return;
+        inorder(root.left);
+        System.out.print(root.data + " ");
+        inorder(root.right);
+    }
+}
+
+class GFG {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int t;
+        t = Integer.parseInt(br.readLine());
+        while (t-- > 0) {
+
+            int n;
+            n = Integer.parseInt(br.readLine());
+
+            Node root = Node.inputTree(br);
+
+            Solution obj = new Solution();
+            int res = obj.pairsViolatingBST(n, root);
+
+            System.out.println(res);
+        }
+    }
+}
+
+// } Driver Code Ends
+
+
+/*
+
+Definition for Binary Tree Node
+class Node
+{
+    int data;
+    Node left;
+    Node right;
+
+    Node(int data)
+    {
+        this.data = data;
+        left = null;
+        right = null;
+    }
+}
+*/
+
+class Solution 
+{
+    int i = 0, count = 0;
+
+
+    public int pairsViolatingBST(int n, Node root) 
+    {
+        i = 0; count = 0;
+        int[] arr = new int[n];
+
+        inOrder(root, arr);
+        mergeSort(arr, 0, n-1);
+
+        return count;
+    }
+
+    public void inOrder(Node root, int[] arr)
+    {
+        if(root == null)
+            return;
+
+        inOrder(root.left, arr);
+
+        arr[i++] = root.data;
+
+        inOrder(root.right, arr);
+    }
+
+    public void mergeSort(int[] arr, int low, int high)
+    {
+        if(low >= high)
+            return;
+
+        int mid = (low+high)/2;
+
+        mergeSort(arr, low, mid);
+        mergeSort(arr, mid+1, high);
+        merge(arr, low, mid, high);
+    }
+
+    public void merge(int[] arr, int low, int mid, int high)
+    {
+        int[] temp = new int[high-low+1];
+        i = low;
+        int j = mid+1, k = 0;
+
+        while(i <= mid && j <= high)
+        {
+            if(arr[i] <= arr[j])
+                temp[k++] = arr[i++];
+            else
+            {
+                count+=(mid-i+1);
+                temp[k++] = arr[j++];
+            }
+        }
+
+        while(i <= mid)
+            temp[k++] = arr[i++];
+
+        while(j <= high)
+            temp[k++] = arr[j++];
+
+        k = 0;
+
+        for(i=low; i<=high; i++, k++)
+            arr[i] = temp[k];
+    }
+}

GeeksForGeeks/April/01-4-24/README.md

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+Time complexity - O(n * logn)
+Space complexity - O(n)

LeetCode/April/01-4-24/README.md

@@ -0,0 +1,2 @@
+Time complexity - O(n)
+Space complexity - O(1)

LeetCode/April/01-4-24/Solution.java

@@ -0,0 +1,17 @@
+class Solution 
+{
+    public int lengthOfLastWord(String s) 
+    {
+        int i = s.length() - 1;
+
+        while (i >= 0 && s.charAt(i) == ' ')
+            --i;
+
+        int lastIndex = i;
+
+        while (i >= 0 && s.charAt(i) != ' ')
+            --i;
+
+        return lastIndex - i;
+    }
+}