LEET code -- Minimum Depth of Binary Tree

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

要判斷該root是不是leaf
因為值接回傳return le>=ri  會變成 不是leaf的誤判(右子樹沒東西  會回傳0 一定最小)

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/** * Definition for a binary tree node. * struct TreeNode { * int val; * struct TreeNode *left; * struct TreeNode *right; * }; */ int minDepth(struct TreeNode* root) { if(root==NULL)return 0; int le=minDepth(root->left); int ri=minDepth(root->right); if(root->left && root->right ) return le>=ri? ri+1:le+1; else if(root->left)return le+1; else return ri+1; }