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 a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    int minDepth(TreeNode* root) {        if(root == NULL){            return 0;        }                if(root->left == NULL && root->right == NULL){            return 1;        }                int lDep = minDepth(root->left);        int rDep = minDepth(root->right);                if(lDep == 0){            return 1+rDep;        }else if(rDep == 0){            return 1+lDep;        }else{            return min(1+lDep,1+rDep);        }    }};