判断一棵二叉树是否是二叉排序树

分析：是否是二叉排序树，即看树的中序遍历是否为递增的即可

typedef struct node{ElemType data;struct node *lchild,*rchild;}BTree;void solve(BTree T,int flag){if(T && flag){solve(T->lchild,flag);//中序遍历左子树if(pre == null)pre = T;//中序遍历的第一个结点不用判断elseif(pre->data < T->data)pre = T;elseflag = false;solve(T->rchild,flag);}}