递归求二叉树中某一节点的后继

public class Main{
	public static int getSucc(BSTNode node,int p){
		if(node==null)return succ;
		in(node,p);
		return succ;
	}
	public void in(BSTNode node,int p){
			if(node==null)return;
			in(node.left,p);
			if(pre==p){
				if(succ!=-1){//之前已经找着
					return;
				}
				succ=node.value;//p的后继为pre的右节点的值
	}
			pre=node.value;
			in(node.right);
	}
private static int succ=-1;
private static int pre=Integer.MIN_VALUE;//记录上一节点的值
}