Leetcode---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.

比较奇葩的设定，要是没有左子树，那么就要算右子树的最小高度。

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