Question:
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 a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
#define INF_MAX 10000000000;
class Solution {
public:
int minDepth(TreeNode* root) {
if(root == 0) return 0;
if(!root -> left) return minDepth(root -> right) + 1;
if(!root -> right) return minDepth(root -> left) + 1;
return min(minDepth(root -> left) + 1 , minDepth(root -> right) + 1);
}
};