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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. struct TreeNode{
  5. 	int data;
  6. 	TreeNode* right;
  7. 	TreeNode* left;
  8. 	TreeNode(int val):left(nullptr),right(nullptr),data(val){};
  9. };
  10.  
  11. void helper(TreeNode* root,vector<int>&curr,vector<vector<int>>&ans){
  12. 	if(!root)return;
  13.  
  14. 	curr.push_back(root->data);
  15. 	if(!root->left && !root->right){
  16. 		ans.push_back(curr);
  17. 	}else{
  18. 		helper(root->left,curr,ans);
  19. 		helper(root->right,curr,ans);
  20. 	}
  21. 	curr.pop_back();
  22. }
  23. vector<vector<int>>print(TreeNode* root){
  24. 	vector<vector<int>>ans;
  25. 	if(!root)return ans;
  26.  
  27. 	vector<int>curr;
  28. 	helper(root,curr,ans);
  29. 	return ans;
  30. }
  31. TreeNode* buildTree(){
  32. 	int x;cin>>x;
  33. 	if(x == -1)return nullptr;
  34.  
  35. 	TreeNode* root = new TreeNode(x);
  36.  
  37. 	queue<TreeNode*>q;
  38. 	q.push(root);
  39.  
  40. 	while(!q.empty()){
  41. 		auto u= q.front();q.pop();
  42.  
  43. 		if(cin>>x && x!=-1){
  44. 			u->left = new TreeNode(x);
  45. 			q.push(u->left);
  46. 		}
  47.  
  48. 		if(cin>>x && x!=-1){
  49. 			u->right = new TreeNode(x);
  50. 			q.push(u->right);
  51. 		}
  52. 	}
  53. 	return root;
  54. }
  55. int main() {
  56. 	TreeNode* root = buildTree();
  57. 	vector<vector<int>>ans = print(root);
  58.  
  59. 	for(auto x : ans){
  60. 		for(int y : x){
  61. 			cout<<y<< " ";
  62. 		}
  63. 		cout<<endl;
  64. 	}
  65. 	return 0;
  66. }
Success #stdin #stdout 0s 5316KB
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https://ideone.com/kqFTa2
language:
C++14 (gcc 8.3)
created:
4 hours ago
visibility:
public

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