Added some code

leetcode/problems/cpp/duplicate-zeros.cpp

@@ -0,0 +1,27 @@
+// by @codeAbinash
+// Time : O(n)
+// Space : O(n)
+
+#include "algorithm"
+#include "vector"
+using namespace std;
+
+
+class Solution {
+public:
+  void duplicateZeros(vector<int>& arr) {
+    int zeroCount = count(arr.begin(), arr.end(), 0);
+    int size = arr.size();
+    int newSize = size + zeroCount;
+    arr.resize(newSize);
+
+    int i = size - 1;
+    while (i >= 0) {
+      if (!arr[i]) zeroCount--;
+      if (i + zeroCount < newSize) arr[i + zeroCount] = arr[i];
+      if (!arr[i] && i + zeroCount + 1 < newSize) arr[i + zeroCount + 1] = arr[i];
+      i--;
+    }
+    arr.resize(size);
+  }
+};

leetcode/problems/cpp/find-duplicate-subtrees.cpp

@@ -0,0 +1,37 @@
+// by @codeAbinash
+// Time : O(n^2)
+// Space : O(n)
+
+#include "vector"
+#include "string"
+#include "unordered_map"
+using namespace std;
+
+struct TreeNode {
+  int val;
+  TreeNode* left;
+  TreeNode* right;
+  TreeNode() : val(0), left(nullptr), right(nullptr) {}
+  TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+  TreeNode(int x, TreeNode* left, TreeNode* right) : val(x), left(left), right(right) {}
+};
+
+class Solution {
+public:
+  vector<TreeNode*> res;
+  unordered_map<string, int> map;
+  vector<TreeNode*> findDuplicateSubtrees(TreeNode* root) {
+    dfs(root);
+    return res;
+  }
+
+  string dfs(TreeNode* root) {
+    if (!root) return "#";
+    string left = dfs(root->left);
+    string right = dfs(root->right);
+    string subTree = left + "," + right + "," + to_string(root->val);
+    if (map[subTree] == 1) res.push_back(root);
+    map[subTree]++;
+    return subTree;
+  }
+};

leetcode/problems/cpp/merge-sorted-array.cpp

@@ -1,33 +1,14 @@
-// by @CodeAntu
-// time complexity o(m+n)
-// space complexity o(1)
-
-
-
-void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
-   int i = m - 1;
-   int j = n - 1;
-   int k = m + n - 1;
-
-   while (i >= 0 && j >= 0)
-   {
-      if (nums1[i] > nums2[j])
-      {
-         nums1[k] = nums1[i];
-         i--;
-      } else {
-         nums1[k] = nums2[j];
-         j--;
-      }
-      k--;
-   }
-   if (i < 0)
-   {
-      while (j >= 0)
-      {
-         nums1[k] = nums2[j];
-         j--;
-         k--;
-      }
-   }
-}
+#include "vector"
+using namespace std;
+
+class Solution {
+public:
+  void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
+    int i = m - 1, j = n - 1, k = m + n - 1;
+    while (i >= 0 && j >= 0) {
+      if (nums1[i] > nums2[j]) nums1[k--] = nums1[i--];
+      else nums1[k--] = nums2[j--];
+    }
+    while (j >= 0) nums1[k--] = nums2[j--];
+  }
+};