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.
Note: A leaf is a node with no children.
Example:
Given binary tree[3,9,20,null,null,15,7],
3
/ \
9 20
/ \
15 7
return its minimum depth = 2.
/**
* 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\(TreeNode\* root\) {
int result=0;
if \(root==NULL\){
return 0;
}
else{
result=1;
if \(\(root->left!=NULL\) && \(root->right!=NULL\)\){
result+=min\(minDepth\(root->left\),minDepth\(root->right\)\);
}
else if \(\(root->left!=NULL\) && \(root->right==NULL\)\){
result+=minDepth\(root->left\);
}
else if \(\(root->left==NULL\) && \(root->right!=NULL\)\) {
result+=minDepth\(root->right\);
}
else{
}
}
return result;
}
};