要求:根据中序和后序遍历序列构建一棵二叉树
代码如下:
struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x): val(x),left(NULL), right(NULL) {}
}; typedef vector<int>::iterator Iter; TreeNode *buildTreeFromInorderPostorder(vector<int> &inorder, vector<int> &postorder)
{
return buildBinaryTreeResur(inorder.begin(), inorder.end(), postorder.begin(), postorder.end());
} TreeNode *buildBinaryTreeResur(Iter istart, Iter iend, Iter pstart, Iter pend)
{
if (istart == iend || pstart == pend)
return NULL;
int ival = *(pend-);
Iter ptemp = find(istart, iend, ival);
TreeNode *res = new TreeNode(ival);
res->left = buildBinaryTreeResur(istart, ptemp, pstart, pstart+(ptemp-istart));
res->right = buildBinaryTreeResur(ptemp+, iend, pstart+(ptemp-istart), pend-);
return res;
}