public class Solution {
public int minDepth(TreeNode root) {
if(root==null) return 0;
if(root.left==null) return minDepth(root.right)+1;
if(root.right==null) return minDepth(root.left)+1;
return Math.min(minDepth(root.right), minDepth(root.left)) + 1;
}
}
public class Solution {
public int minDepth(TreeNode root) {
if(root == null) {
return 0;
}
if(root.left == null && root.right == null) {
return 1;
}
int l,r;
if(root.left != null) {
l = minDepth(root.left);
} else {
l = Integer.MAX_VALUE;
}
if(root.right != null) {
r = minDepth(root.right);
} else {
r = Integer.MAX_VALUE;
}
return l>=r?r+1:l+1;
}
}