.()p:=p^lchild ()()p:=Sdata[stop]^rchild ()stop=
()*ppos // 根结点 ()rpos=ipos ()rposipos ()ipos ()ppos+
()top> ()stack[top]:=nd^right ()nd^left<>NIL ()top:=top+ (左子树非空)
() p<>thr // 未循环结束 ()p>ltag= ()p>lchild()p>rtag= && p>rchild!=thr () p=p>rchild ()p=p>rchild
若p^rtag=则p^rchild 为后继否则p的后继是p的右子树中最左下的结点
()q=p^rchild ()q^ltag= () q^lchild
.()tree>lchild ()null ()pre>rchild()pre>rtag= () pre>right=tree; () tree>right (注()和()顺序可换)
.()node>rflag== ()*x=bt () *x=node>right
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