111 Minimum Depth of Binary Tree

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) {
if(root == NULL) return 0;
if(root->left != NULL && root ->right != NULL)
{
int left = 1 + minDepth(root->left);
int right = 1 + minDepth(root->right);
return min(left,right);
}
else if(root->left != NULL && root->right == NULL)
return 1 + minDepth(root->left);
else if(root->left == NULL && root->right != NULL)
return 1 + minDepth(root->right);
return 1;
}
};