Create Binary Tree From Descriptions LeetCode solution in C++

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class Solution {
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 public:
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  TreeNode *createBinaryTree(vector<vector<int>> &descriptions) {
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    unordered_map<int, TreeNode *> getNode; // to check if node alredy exist
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    unordered_map<int, bool> isChild;       // to check if node has parent or not
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    for (auto &v : descriptions) {
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      if (getNode.count(v[0]) == 0) {
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        TreeNode *par = new TreeNode(v[0]);
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        getNode[v[0]] = par;
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      }
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      if (getNode.count(v[1]) == 0) {
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        TreeNode *child = new TreeNode(v[1]);
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        getNode[v[1]] = child;
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      }
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      if (v[2] == 1)
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        getNode[v[0]]->left = getNode[v[1]]; // left-child
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      else
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        getNode[v[0]]->right = getNode[v[1]]; // right-child
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      isChild[v[1]] = true;
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    }
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    TreeNode *ans = NULL;
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    for (auto &v : descriptions) {
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      if (isChild[v[0]] != true) { // if node has no parent then this is root node
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        ans = getNode[v[0]];
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        break;
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      }
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    }
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    return ans;
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  }
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};