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Tree DFS
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| // Iteration | |
| bool hasPathSum(TreeNode* root, int sum) { | |
| if(!root) return false; | |
| stack<TreeNode*>s{{root}}; | |
| while(!s.empty()){ | |
| TreeNode* tmp = s.top(); | |
| s.pop(); | |
| if(!tmp->left && !tmp->right && tmp->val == sum) | |
| return true; | |
| if(tmp->left){ | |
| tmp->left->val += tmp->val; | |
| s.push(tmp->left); | |
| } | |
| if(tmp->right){ | |
| tmp->right->val += tmp->val; | |
| s.push(tmp->right); | |
| } | |
| } | |
| return false; | |
| } | |
| // Recursion | |
| bool hasPathSum(TreeNode* root, int sum) { | |
| if(!root) | |
| return false; | |
| if(!root->left && !root->right && root->val == sum) | |
| return true; | |
| return hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val); | |
| } |
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