`{"id":"582ab512-83b8-4ea2-9cc2-ab89d5e50b51","name":"Print Single Child Nodes","description":"1. You are given a partially written BinaryTree class.\r\n2. You are required to complete the body of printSingleChildNodes function. The function is expected to print in separate lines, all such nodes which are only child of their parent. Use preorder for traversal.\r\n3. Input and Output is managed for you.","inputFormat":"Input is managed for you.","outputFormat":"Output is managed for you.","constraints":"None","sampleCode":{"cpp":{"code":"#include <iostream>\n#include <vector>\n#include <algorithm>\n#include <queue>\n\nusing namespace std;\n\nclass Node\n{\npublic:\n int data;\n Node *left = nullptr;\n Node *right = nullptr;\n Node(int data,Node *left,Node *right)\n {\n this->data = data;\n this->left = left;\n this->right = right;\n }\n};\n\n int idx = 0;\nNode *constructTree(vector<int> &arr)\n{\n\n if (idx == arr.size() || arr[idx] == -1)\n {\n idx++;\n return nullptr;\n }\n Node *node = new Node(arr[idx++],nullptr,nullptr);\n node->left = constructTree(arr);\n node->right = constructTree(arr);\n return node;\n}\n\nvoid display(Node *node) {\n if (node == nullptr) {\n return;\n }\n\n string str = \"\";\n str += node->left == nullptr ? \".\" : to_string(node->left->data) + \"\";\n str += \" <- \" + to_string(node->data) + \" -> \";\n str += node->right == nullptr ? \".\" : to_string(node->right->data) + \"\";\n cout<<str<<endl;\n\n display(node->left);\n display(node->right);\n}\n\n void printSingleChildNodes(Node *node, Node *parent){\n // write your code here\n\n }\n\n int main()\n {\n vector<int> arr;\n int n;\n cin>>n;\n \n for(int i = 0; i<n; i++){\n string inp;\n cin>>inp;\n if(inp != \"n\"){\n arr.push_back(stoi(inp));\n }\n else{\n arr.push_back(-1);\n }\n }\n \n \n Node *root = constructTree(arr);\n printSingleChildNodes(root, nullptr);\n }"},"java":{"code":"import java.io.*;\r\nimport java.util.*;\r\n\r\npublic class Main {\r\n public static class Node {\r\n int data;\r\n Node left;\r\n Node right;\r\n\r\n Node(int data, Node left, Node right) {\r\n this.data = data;\r\n this.left = left;\r\n this.right = right;\r\n }\r\n }\r\n\r\n public static class Pair {\r\n Node node;\r\n int state;\r\n\r\n Pair(Node node, int state) {\r\n this.node = node;\r\n this.state = state;\r\n }\r\n }\r\n\r\n public static Node construct(Integer[] arr) {\r\n Node root = new Node(arr, null, null);\r\n Pair rtp = new Pair(root, 1);\r\n\r\n Stack<Pair> st = new Stack<>();\r\n st.push(rtp);\r\n\r\n int idx = 0;\r\n while (st.size() > 0) {\r\n Pair top = st.peek();\r\n if (top.state == 1) {\r\n idx++;\r\n if (arr[idx] != null) {\r\n top.node.left = new Node(arr[idx], null, null);\r\n Pair lp = new Pair(top.node.left, 1);\r\n st.push(lp);\r\n } else {\r\n top.node.left = null;\r\n }\r\n\r\n top.state++;\r\n } else if (top.state == 2) {\r\n idx++;\r\n if (arr[idx] != null) {\r\n top.node.right = new Node(arr[idx], null, null);\r\n Pair rp = new Pair(top.node.right, 1);\r\n st.push(rp);\r\n } else {\r\n top.node.right = null;\r\n }\r\n\r\n top.state++;\r\n } else {\r\n st.pop();\r\n }\r\n }\r\n\r\n return root;\r\n }\r\n\r\n public static void display(Node node) {\r\n if (node == null) {\r\n return;\r\n }\r\n\r\n String str = \"\";\r\n str += node.left == null ? \".\" : node.left.data + \"\";\r\n str += \" <- \" + node.data + \" -> \";\r\n str += node.right == null ? \".\" : node.right.data + \"\";\r\n System.out.println(str);\r\n\r\n display(node.left);\r\n display(node.right);\r\n }\r\n\r\n public static void printSingleChildNodes(Node node, Node parent){\r\n // write your code here\r\n }\r\n\r\n public static void main(String[] args) throws Exception {\r\n BufferedReader br = new BufferedReader(new InputStreamReader(System.in));\r\n int n = Integer.parseInt(br.readLine());\r\n Integer[] arr = new Integer[n];\r\n String[] values = br.readLine().split(\" \");\r\n for (int i = 0; i < n; i++) {\r\n if (values[i].equals(\"n\") == false) {\r\n arr[i] = Integer.parseInt(values[i]);\r\n } else {\r\n arr[i] = null;\r\n }\r\n }\r\n\r\n Node root = construct(arr);\r\n printSingleChildNodes(root, null);\r\n }\r\n\r\n}"},"python":{"code":"class Node:\n def __init__(self,data,left,right):\n self.data = data\n self.left = left\n self.right = right\n\nidx = 0\n\ndef construct(arr):\n global idx\n if idx == len(arr) or arr[idx] == -1:\n idx = idx+1\n return None\n node = Node(arr[idx],None,None)\n idx = idx+1\n node.left = construct(arr)\n node.right = construct(arr)\n return node\n\n\n\ndef display(node):\n if node:\n s = \"\"\n s += \".\" if node.left == None else str(node.left.data)\n s += \" <- \" + str(node.data) + \" -> \"\n s += \".\" if node.right == None else str(node.right.data)\n print(s)\n display(node.left)\n display(node.right)\n\ndef printSingleChildNodes(node,parent):\n # write your code here\n if node==None:\n return\n if parent!=None and parent.left==None and parent.right!=None:\n print(node.data)\n return\n if parent!=None and parent.left!=None and parent.right==None:\n print(node.data)\n return\n \n printSingleChildNodes(node.left,node)\n printSingleChildNodes(node.right,node)\n \nif __name__ == '__main__':\n\n n = int(input())\n s = input()\n l = list(s.split(\" \"))\n arr = []\n for i in range(len(l)):\n if(l[i] == 'n'):\n arr.append(-1)\n \n elif(l[i] == 'n\\r'):\n arr.append(-1)\n \n else: \n arr.append(int(l[i]))\n \n root = construct(arr)\n printSingleChildNodes(root, None);"}},"points":10,"difficulty":"easy","sampleInput":"19\r\n50 25 12 n n 37 30 n n n 75 62 n 70 n n 87 n n","sampleOutput":"30\r\n70","questionVideo":"https://www.youtube.com/embed/EF3F-8jBQWQ","hints":[],"associated":[{"id":"3bbede70-a676-47e4-ac32-b3facc31c41c","name":"What do we have to pass in function?","slug":"what-do-we-have-to-pass-in-function","type":4},{"id":"3fe4ff6c-f579-4849-a301-65191c910edd","name":"When will the exception come in the output?","slug":"when-will-the-exception-come-in-the-output","type":4},{"id":"7b400687-1310-4d89-b3aa-f74c0f96c914","name":"Which type of node do we have to print?","slug":"which-type-of-node-do-we-have-to-print","type":4},{"id":"b52a5fbe-07e2-4e49-8097-a28d371a209d","name":"What will be the base condition?","slug":"what-will-be-the-base-condition","type":4}],"solutionSeen":false,"tags":[],"meta":{"path":[{"id":0,"name":"home"},{"id":"0c54b191-7b99-4f2c-acb3-e7f2ec748b2a","name":"Data Structures and Algorithms","slug":"data-structures-and-algorithms","type":0},{"id":"b042fe97-356f-41ed-80fd-abacd61fc234","name":"Binary Tree For Beginners","slug":"binary-tree-for-beginners","type":0},{"id":"4cf395c2-d139-42bb-aecc-b3cda2f5513f","name":"Print Single Child Nodes","slug":"print-single-child-nodes","type":1}],"next":{"id":"24fdc673-45d7-4d17-b4b8-8f3f4b6abe6b","name":"Print Single Child Nodes","type":3,"slug":"print-single-child-nodes"},"prev":{"id":"a0603d6b-ed41-4709-9afb-00c0f173ac64","name":"Transform to Normal from Left Cloned Tree","type":3,"slug":"transform-to-normal-from-left-cloned-tree"}}}`

# Print Single Child Nodes

1. You are given a partially written BinaryTree class. 2. You are required to complete the body of printSingleChildNodes function. The function is expected to print in separate lines, all such nodes which are only child of their parent. Use preorder for traversal. 3. Input and Output is managed for you.

`{"id":"582ab512-83b8-4ea2-9cc2-ab89d5e50b51","name":"Print Single Child Nodes","description":"1. You are given a partially written BinaryTree class.\r\n2. You are required to complete the body of printSingleChildNodes function. The function is expected to print in separate lines, all such nodes which are only child of their parent. Use preorder for traversal.\r\n3. Input and Output is managed for you.","inputFormat":"Input is managed for you.","outputFormat":"Output is managed for you.","constraints":"None","sampleCode":{"cpp":{"code":"#include <iostream>\n#include <vector>\n#include <algorithm>\n#include <queue>\n\nusing namespace std;\n\nclass Node\n{\npublic:\n int data;\n Node *left = nullptr;\n Node *right = nullptr;\n Node(int data,Node *left,Node *right)\n {\n this->data = data;\n this->left = left;\n this->right = right;\n }\n};\n\n int idx = 0;\nNode *constructTree(vector<int> &arr)\n{\n\n if (idx == arr.size() || arr[idx] == -1)\n {\n idx++;\n return nullptr;\n }\n Node *node = new Node(arr[idx++],nullptr,nullptr);\n node->left = constructTree(arr);\n node->right = constructTree(arr);\n return node;\n}\n\nvoid display(Node *node) {\n if (node == nullptr) {\n return;\n }\n\n string str = \"\";\n str += node->left == nullptr ? \".\" : to_string(node->left->data) + \"\";\n str += \" <- \" + to_string(node->data) + \" -> \";\n str += node->right == nullptr ? \".\" : to_string(node->right->data) + \"\";\n cout<<str<<endl;\n\n display(node->left);\n display(node->right);\n}\n\n void printSingleChildNodes(Node *node, Node *parent){\n // write your code here\n\n }\n\n int main()\n {\n vector<int> arr;\n int n;\n cin>>n;\n \n for(int i = 0; i<n; i++){\n string inp;\n cin>>inp;\n if(inp != \"n\"){\n arr.push_back(stoi(inp));\n }\n else{\n arr.push_back(-1);\n }\n }\n \n \n Node *root = constructTree(arr);\n printSingleChildNodes(root, nullptr);\n }"},"java":{"code":"import java.io.*;\r\nimport java.util.*;\r\n\r\npublic class Main {\r\n public static class Node {\r\n int data;\r\n Node left;\r\n Node right;\r\n\r\n Node(int data, Node left, Node right) {\r\n this.data = data;\r\n this.left = left;\r\n this.right = right;\r\n }\r\n }\r\n\r\n public static class Pair {\r\n Node node;\r\n int state;\r\n\r\n Pair(Node node, int state) {\r\n this.node = node;\r\n this.state = state;\r\n }\r\n }\r\n\r\n public static Node construct(Integer[] arr) {\r\n Node root = new Node(arr, null, null);\r\n Pair rtp = new Pair(root, 1);\r\n\r\n Stack<Pair> st = new Stack<>();\r\n st.push(rtp);\r\n\r\n int idx = 0;\r\n while (st.size() > 0) {\r\n Pair top = st.peek();\r\n if (top.state == 1) {\r\n idx++;\r\n if (arr[idx] != null) {\r\n top.node.left = new Node(arr[idx], null, null);\r\n Pair lp = new Pair(top.node.left, 1);\r\n st.push(lp);\r\n } else {\r\n top.node.left = null;\r\n }\r\n\r\n top.state++;\r\n } else if (top.state == 2) {\r\n idx++;\r\n if (arr[idx] != null) {\r\n top.node.right = new Node(arr[idx], null, null);\r\n Pair rp = new Pair(top.node.right, 1);\r\n st.push(rp);\r\n } else {\r\n top.node.right = null;\r\n }\r\n\r\n top.state++;\r\n } else {\r\n st.pop();\r\n }\r\n }\r\n\r\n return root;\r\n }\r\n\r\n public static void display(Node node) {\r\n if (node == null) {\r\n return;\r\n }\r\n\r\n String str = \"\";\r\n str += node.left == null ? \".\" : node.left.data + \"\";\r\n str += \" <- \" + node.data + \" -> \";\r\n str += node.right == null ? \".\" : node.right.data + \"\";\r\n System.out.println(str);\r\n\r\n display(node.left);\r\n display(node.right);\r\n }\r\n\r\n public static void printSingleChildNodes(Node node, Node parent){\r\n // write your code here\r\n }\r\n\r\n public static void main(String[] args) throws Exception {\r\n BufferedReader br = new BufferedReader(new InputStreamReader(System.in));\r\n int n = Integer.parseInt(br.readLine());\r\n Integer[] arr = new Integer[n];\r\n String[] values = br.readLine().split(\" \");\r\n for (int i = 0; i < n; i++) {\r\n if (values[i].equals(\"n\") == false) {\r\n arr[i] = Integer.parseInt(values[i]);\r\n } else {\r\n arr[i] = null;\r\n }\r\n }\r\n\r\n Node root = construct(arr);\r\n printSingleChildNodes(root, null);\r\n }\r\n\r\n}"},"python":{"code":"class Node:\n def __init__(self,data,left,right):\n self.data = data\n self.left = left\n self.right = right\n\nidx = 0\n\ndef construct(arr):\n global idx\n if idx == len(arr) or arr[idx] == -1:\n idx = idx+1\n return None\n node = Node(arr[idx],None,None)\n idx = idx+1\n node.left = construct(arr)\n node.right = construct(arr)\n return node\n\n\n\ndef display(node):\n if node:\n s = \"\"\n s += \".\" if node.left == None else str(node.left.data)\n s += \" <- \" + str(node.data) + \" -> \"\n s += \".\" if node.right == None else str(node.right.data)\n print(s)\n display(node.left)\n display(node.right)\n\ndef printSingleChildNodes(node,parent):\n # write your code here\n if node==None:\n return\n if parent!=None and parent.left==None and parent.right!=None:\n print(node.data)\n return\n if parent!=None and parent.left!=None and parent.right==None:\n print(node.data)\n return\n \n printSingleChildNodes(node.left,node)\n printSingleChildNodes(node.right,node)\n \nif __name__ == '__main__':\n\n n = int(input())\n s = input()\n l = list(s.split(\" \"))\n arr = []\n for i in range(len(l)):\n if(l[i] == 'n'):\n arr.append(-1)\n \n elif(l[i] == 'n\\r'):\n arr.append(-1)\n \n else: \n arr.append(int(l[i]))\n \n root = construct(arr)\n printSingleChildNodes(root, None);"}},"points":10,"difficulty":"easy","sampleInput":"19\r\n50 25 12 n n 37 30 n n n 75 62 n 70 n n 87 n n","sampleOutput":"30\r\n70","questionVideo":"https://www.youtube.com/embed/EF3F-8jBQWQ","hints":[],"associated":[{"id":"3bbede70-a676-47e4-ac32-b3facc31c41c","name":"What do we have to pass in function?","slug":"what-do-we-have-to-pass-in-function","type":4},{"id":"3fe4ff6c-f579-4849-a301-65191c910edd","name":"When will the exception come in the output?","slug":"when-will-the-exception-come-in-the-output","type":4},{"id":"7b400687-1310-4d89-b3aa-f74c0f96c914","name":"Which type of node do we have to print?","slug":"which-type-of-node-do-we-have-to-print","type":4},{"id":"b52a5fbe-07e2-4e49-8097-a28d371a209d","name":"What will be the base condition?","slug":"what-will-be-the-base-condition","type":4}],"solutionSeen":false,"tags":[],"meta":{"path":[{"id":0,"name":"home"},{"id":"0c54b191-7b99-4f2c-acb3-e7f2ec748b2a","name":"Data Structures and Algorithms","slug":"data-structures-and-algorithms","type":0},{"id":"b042fe97-356f-41ed-80fd-abacd61fc234","name":"Binary Tree For Beginners","slug":"binary-tree-for-beginners","type":0},{"id":"4cf395c2-d139-42bb-aecc-b3cda2f5513f","name":"Print Single Child Nodes","slug":"print-single-child-nodes","type":1}],"next":{"id":"24fdc673-45d7-4d17-b4b8-8f3f4b6abe6b","name":"Print Single Child Nodes","type":3,"slug":"print-single-child-nodes"},"prev":{"id":"a0603d6b-ed41-4709-9afb-00c0f173ac64","name":"Transform to Normal from Left Cloned Tree","type":3,"slug":"transform-to-normal-from-left-cloned-tree"}}}` Editor

# Print Single Child Nodes

easy

1. You are given a partially written BinaryTree class. 2. You are required to complete the body of printSingleChildNodes function. The function is expected to print in separate lines, all such nodes which are only child of their parent. Use preorder for traversal. 3. Input and Output is managed for you.

None

## Format

### Input

Input is managed for you.

### Output

Output is managed for you.

## Example

Sample Input

```.css-23h8hz{color:inherit;font-size:0.875rem;line-height:1.125rem;letter-spacing:0.016rem;font-weight:var(--chakra-fontWeights-normal);white-space:pre-wrap;}19 50 25 12 n n 37 30 n n n 75 62 n 70 n n 87 n n```

### Sample Output

```.css-3oaykw{color:var(--chakra-colors-active-primary);font-size:0.875rem;line-height:1.125rem;letter-spacing:0.016rem;font-weight:var(--chakra-fontWeights-normal);white-space:pre-wrap;font-family:Monospace;}30 70```

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