//二叉树的叶结点:度为0的结点。 void PreorderPrintLeaves( BinTree BT ) { if(BT==NULL) //如果传下来根节点就是空,直接返回; return; //如果存在子节点,一直下去 if(BT->Left) PreorderPrintLeaves(BT->Left); if(BT->Right) PreorderPrintLeaves(BT->Right); if(BT->Left==NULL&&BT->Right==NULL) //如果是输出就好啦 printf(" %c",BT->Data); }