有序数组转换为平衡二叉搜索树

有一个增序排列的数组，将其转换为平衡二叉搜索树。

class Node{public:Node(int v){value = v;left = NULL;right = NULL;}private:int value;Node *left;Node *right;};Node* sortedArrayToBST(int a[], int left, int right){if (left > right){return NULL;}int mid = left + (right-left)/2;Node *root = new Node(a[mid]);root->left = sortedArrayToBST(a, left, mid-1);root->right = sortedArrayToBST(a, mid+1, right);return root;}