TreeNode *buildBinaryTree(int beginIn, int beginPost, int len){
if(len <= 0){
return NULL;
}
TreeNode *root = new TreeNode(post[beginPost + len - 1]);
int rootPos = findRoot(post[beginPost + len - 1], beginIn, len);
if(rootPos == -1){
return NULL;
}
int newLenLeft = rootPos;
int newLenRight = len - newLenLeft - 1;
root->left = buildBinaryTree(beginIn, beginPost, newLenLeft);
root->right = buildBinaryTree(beginIn + rootPos + 1, beginPost + newLenLeft, newLenRight);
return root;
}
TreeNode *buildBinaryTree(int beginIn, int beginPre, int len){
if(len <= 0){
return NULL;
}
int rootValue = pre[beginPre];
TreeNode *root = new TreeNode(rootValue);
int rootPos = findRoot(rootValue, beginIn, len);
if(rootPos == -1){
return NULL;
}
int newLenLeft = rootPos;
int newLenRight = len - newLenLeft - 1;
root->left = buildBinaryTree(beginIn, beginPre + 1, newLenLeft);
root->right = buildBinaryTree(beginIn + newLenLeft + 1, beginPre + newLenLeft + 1, newLenRight);
return root;
}
TreeNode *buildTree(vector<int> &preorder, vector<int> &inorder) {
if(inorder.size() == 0 ||
preorder.size() == 0 ||
inorder.size() != preorder.size()){
return NULL;
}
in = inorder;
pre = preorder;
return buildBinaryTree(0, 0, in.size());
}
int main(int argc, char const *argv[])
{
int val;
scanf("%d", &val);
tree = getNFillNode(val);
pin_node q, p;
while(1) {
scanf("%d", &val);
buildBinaryTree(tree, val);
p = NULL;
}
printf("%d\n", tree->val);
return 0;
}
