day 2

Author: sachuverma

Diff for: DSA Crack Sheet/README.md

@@ -213,6 +213,7 @@
 - [Merge Two Balanced Binary Search Trees](https://www.geeksforgeeks.org/merge-two-balanced-binary-search-trees/ "view post")
 - [Kth largest element in BST](https://practice.geeksforgeeks.org/problems/kth-largest-element-in-bst/1# "view question") - [Cpp Solution](./solutions/Kth%20largest%20element%20in%20BST.cpp)
 - [k-th smallest element in BST](https://practice.geeksforgeeks.org/problems/find-k-th-smallest-element-in-bst/1 "view question") - [Cpp Solution](./solutions/k-th%20smallest%20element%20in%20BST.cpp)
+- [Brothers From Different Roots](https://practice.geeksforgeeks.org/problems/brothers-from-different-root/1# "view question") - [Cpp Solution](./solutions/Brothers%20From%20Different%20Roots.cpp)
 - []( "view question") - [Cpp Solution](./solutions/.cpp)
 
 ### Greedy Method

Diff for: DSA Crack Sheet/solutions/Brothers From Different Roots.cpp

@@ -0,0 +1,80 @@
+/*
+Brothers From Different Roots
+=============================
+
+Given two BSTs containing N1 and N2 distinct nodes respectively and given a value x. Your task is to complete the function countPairs(), that returns the count of all pairs from both the BSTs whose sum is equal to x.
+
+Examples:
+Input : BST 1:    5        
+                /   \      
+               3     7      
+              / \   / \    
+             2  4  6   8   
+
+        BST 2:    10        
+                /   \      
+               6     15      
+              / \   /  \    
+             3  8  11  18
+        x = 16
+    
+Output : 3
+The pairs are:
+(5, 11), (6, 10) and (8, 8)
+Input:
+The function takes three arguments as input, first the reference pointer to the root(root1) of the BST1, then reference pointer to the root(root2) of the BST2 and last the element X.
+There will be T test cases and for each test case the function will be called separately.
+
+Output:
+For each test cases print the required number of pairs on new line.
+
+Constraints:
+1<=T<=100
+1<=N<=103
+
+Example:
+Input:
+2
+7
+5 3 7 2 4 6 8
+7
+10 6 15 3 8 11 18
+16
+6
+10 20 30 40 5 1
+5
+25 35 10 15 5
+30
+Output:
+3
+2
+*/
+
+bool search(Node *root, int x)
+{
+  if (!root)
+    return false;
+  if (root->data == x)
+    return true;
+  else if (root->data < x)
+    return search(root->right, x);
+  return search(root->left, x);
+}
+
+void dfs(Node *root1, Node *root2, int x, int &ans)
+{
+  if (!root1)
+    return;
+  int tar = root1->data;
+  if (search(root2, x - tar))
+    ans++;
+  dfs(root1->left, root2, x, ans);
+  dfs(root1->right, root2, x, ans);
+}
+
+int countPairs(Node *root1, Node *root2, int x)
+{
+  int ans = 0;
+  dfs(root1, root2, x, ans);
+  return ans;
+}

Diff for: Leetcode Daily Challenge/July-2021/02. Find K Closest Elements.cpp

@@ -0,0 +1,43 @@
+/*
+Find K Closest Elements
+=======================
+
+Given a sorted integer array arr, two integers k and x, return the k closest integers to x in the array. The result should also be sorted in ascending order.
+
+An integer a is closer to x than an integer b if:
+
+|a - x| < |b - x|, or
+|a - x| == |b - x| and a < b
+
+Example 1:
+Input: arr = [1,2,3,4,5], k = 4, x = 3
+Output: [1,2,3,4]
+
+Example 2:
+Input: arr = [1,2,3,4,5], k = 4, x = -1
+Output: [1,2,3,4]
+
+Constraints:
+1 <= k <= arr.length
+1 <= arr.length <= 104
+arr is sorted in ascending order.
+-104 <= arr[i], x <= 104
+*/
+
+class Solution
+{
+public:
+  vector<int> findClosestElements(vector<int> &arr, int k, int x)
+  {
+    sort(arr.begin(), arr.end(), [x](int &a, int &b)
+         {
+           if (abs(a - x) == abs(b - x))
+             return a < b;
+           return abs(a - x) < abs(b - x);
+         });
+
+    vector<int> ans = vector<int>(arr.begin(), arr.begin() + k);
+    sort(ans.begin(), ans.end());
+    return ans;
+  }
+};

Diff for: Leetcode Daily Challenge/July-2021/README.md

@@ -3,3 +3,4 @@
 | Day | Question Links                                                                                                             |           Solutions            |
 | :-: | :------------------------------------------------------------------------------------------------------------------------- | :----------------------------: |
 | 1.  | [Gray Code](https://leetcode.com/explore/challenge/card/july-leetcoding-challenge-2021/608/week-1-july-1st-july-7th/3799/) | [cpp](./01.%20Gray%20Code.cpp) |
+| 2.  | [Find K Closest Elements](https://leetcode.com/explore/challenge/card/july-leetcoding-challenge-2021/608/week-1-july-1st-july-7th/3800/) | [cpp](./02.%20Find%20K%20Closest%20Elements.cpp) |