[OJ.leetcode] minimum-depth-of-binary-tree

https://oj.leetcode.com/problems/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. 

  /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int minDepth(TreeNode *root) { return findMinimumDepth(root,1); } int findMinimumDepth(TreeNode* root, int depth) { if(root == NULL) return 0; int left = INT_MAX, right = INT_MAX; if(root->left != NULL) { left = findMinimumDepth(root->left, depth+1); } if(root->right != NULL) { right = findMinimumDepth(root->right, depth+1); } if(root->left == NULL && root->right == NULL) return depth; return min(left, right); } };