二叉搜索树的最短路径，从根节点到叶子节点

public int minPathSum(TreeNode root) {    if(root==null)        return -1;   return getLength(root,0);}

private int getLength(TreeNode root, int curLen) {int minLeft=-1;int minRight=-1;if(root.left!=null){minLeft=getLength(root.left,root.val+curLen);}if(root.right!=null){minRight=getLength(root.right,root.val+curLen);}if(root.left==null&&root.right==null){return curLen+root.val;}if(root.left==null){return minRight;}if(root.right==null){return minLeft;}return minLeft>minRight?minRight:minLeft;}

转自：http://www.cnblogs.com/xiangyangzhu/