[leetcode] 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.

class Solution {
public:
    int minDepth(TreeNode *root) {
		// Start typing your C/C++ solution below
		// DO NOT write int main() function
		int left,right;
		if(root==NULL)
			return 0;
		if(!root->left && !root->right)
			return 1;
		if(!root->left && root->right)
			return minDepth(root->right)+1;
		if(root->left && !root->right)
			return minDepth(root->left)+1;
		else
			return (left=minDepth(root->left))>(right=minDepth(root->right))?right+1:left+1;
	}
};