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 * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    public int minDepth(TreeNode root) {        // Note: The Solution object is instantiated only once and is reused by each test case.           if(root==null){       return 0;       }       else if(root.left==null&&root.right==null){           return 1;       }       else if(root.left==null&&root.right!=null){           return 1+minDepth(root.right);       }       else if(root.left!=null&&root.right==null){           return 1+minDepth(root.left);       }       else {           return minDepth(root.left)>minDepth(root.right)?1+minDepth(root.right):1+minDepth(root.left);       }    }        }