Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.
For example:sum = 22
,
5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1
return
[ [5,4,11,2], [5,8,4,5] ]
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class Solution { public: vector> pathSum(TreeNode* root, int sum) { vector > res; vector tmp; //保存中間結果 tmpFunction(root, sum, tmp, res); return res; } void tmpFunction(TreeNode* root, int sum, vector &tmp, vector >&res){ if (root == NULL) return; tmp.push_back(root->val); if (root->left == NULL && root->right == NULL){ if (root->val == sum) res.push_back(tmp); } tmpFunction(root->left, sum - root->val, tmp, res); tmpFunction(root->right, sum - root->val, tmp, res); tmp.pop_back(); } };