#include 
     
           #include 
      
                 typedef struct TNode     {         int value;         TNode* lchild;         TNode* rchild;     }TNode,*BTree;           //根据先序遍历、中序遍历构建二叉树     BTree rebuild(int preOrder[],int startPre,int endPre,int inOrder[],int startIn,int endIn)     {         //先序遍历和中序遍历长度应相等         if (endPre - startPre != endIn - startIn) return NULL;         //起始位置不应大于末尾位置         if (startPre > endPre) return NULL;         //先序遍历的第一个元素为根节点         BTree tree = (BTree)malloc(sizeof(TNode));         tree->value = preOrder[startPre];         tree->lchild = NULL;         tree->rchild = NULL;         //先序遍历和中序遍历只有一个元素时，返回该节点         if (startPre == endPre) return tree;         //在中序遍历中找到根节点         int index,length;         for (index=startIn;index<=endIn;index++)         {             if (inOrder[index] == preOrder[startPre]) break;         }         //若未找到，返回空         if (index > endIn) return NULL;         //有左子树，递归调用构建左子树         if (index > startIn)          {             length = index-startIn;             tree->lchild = rebuild(preOrder,startPre+1,startPre+1+length-1,inOrder,startIn,startIn+length-1);         }         //有右子树，递归调用构建右子树         if (index < endIn)          {             length = endIn - index;             tree->rchild = rebuild(preOrder,endPre-length+1,endPre,inOrder,endIn-length+1,endIn);         }         return tree;     }          //后序遍历二叉树     void postTraverse(BTree tree)     {         if (tree->lchild != NULL) postTraverse(tree->lchild);         if (tree->rchild != NULL) postTraverse(tree->rchild);         printf("%d ",tree->value);     }          int main()     {         int preOrder[] = {
   1,2,4,5,3,6};         int inOrder[] = {
   4,2,5,1,6,3};         BTree tree = rebuild(preOrder,0,5,inOrder,0,5);         postTraverse(tree);         printf("\n");         return 0;     }