学步园

#include <iostream>
using namespace std;

struct Node
{
	Node() : lchild(0), rchild(0){
		
	}
	Node(char v):val(v), lchild(0), rchild(0){
		
	}
	char val;
	Node *lchild, *rchild;
};

void Rebuild(char *pPreOrder, char * pInOder, int len, Node **pRoot)
{
	if(!pPreOrder || !pInOder)
		return;
	if((*pRoot) == NULL && len >= 1)
	{
		*pRoot = new Node(*pPreOrder);
	}
	if(len <= 1)
		return;
	char *s = pInOder, *e = pInOder + len - 1;
	while(s <= e)
	{
		if(*s == *pPreOrder)
			break;
		s++;
	}
	if(s <= e)
	{
		Rebuild(pPreOrder+1, pInOder, s - pInOder, &((*pRoot)->lchild));
		Rebuild(pPreOrder + (s - pInOder) + 1, s+1, e - s, &((*pRoot)->rchild));
	}
}

void print(Node *root)
{
	if(!root)
		return;
	cout << root->val << " ";
	print(root->lchild);
	print(root->rchild);
}

int main(void)
{
	char pPreOder[] = "abdcef";
	char pInOder[] = "dbaecf";
	int len = strlen(pInOder);
	Node *root = NULL;
	Rebuild(pPreOder, pInOder, len, &root);
	print(root);
	
	return 0;
}