Start LeetCode January Challenge:

Add problems 1 and 2.

solved/LeetCode/Challenges/2020/January/01.cc

@@ -0,0 +1,29 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+class Solution {
+ public:
+  bool canFormArray(vector<int>& arr, vector<vector<int>>& pieces) {
+    int idx = 0;
+    while (idx < arr.size()) {
+      int p_id = -1;
+      for (int i = 0; i < pieces.size(); i++) {
+        if (pieces[i][0] == arr[idx]) {
+          p_id = i;
+          break;
+        }
+      }
+      if (p_id == -1) {
+        return false;
+      }
+      for (int j = 0; j < pieces[p_id].size(); j++) {
+        if (arr[idx] != pieces[p_id][j]) {
+          return false;
+        }
+        idx++;
+      }
+    }
+    return idx == arr.size();
+  }
+};

solved/LeetCode/Challenges/2020/January/02.cc

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+
+struct TreeNode {
+  int val;
+  TreeNode *left;
+  TreeNode *right;
+  TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+};
+
+class Solution {
+ public:
+  TreeNode* getTargetCopy(TreeNode* original, TreeNode* cloned, TreeNode* target) {
+    if (cloned == nullptr) {
+      return nullptr;
+    }
+    if (cloned->val == target->val) {
+      return cloned;
+    }
+    TreeNode* left = getTargetCopy(original, cloned->left, target);
+    if (left != nullptr) {
+      return left;
+    }
+    return getTargetCopy(original, cloned->right, target);
+  }
+};