build_balanced_bst_from_sorted_array.cpp

#include<bits/stdc++.h>
using namespace std;

struct Node {
    int data;
    Node *left, *right;

    Node(int val) {
        data = val;
        left = NULL;
        right = NULL;
    }
};

Node* sortedArrayToBST(int arr[], int start, int end) {
    if(start > end) {
        return NULL;
    }

    int mid = (start+end) / 2;
    Node* root = new Node(arr[mid]);

    root->left = sortedArrayToBST(arr, start, mid-1);
    root->right = sortedArrayToBST(arr, mid+1, end);

    return root;
}

void preorderPrint(Node* root) {
    if(root == NULL) {
        return;
    }

    cout<<root->data<<" ";
    preorderPrint(root->left);
    preorderPrint(root->right);
}


int main() {

    int arr[] = {10, 20, 30, 40, 50};
    Node* root = sortedArrayToBST(arr, 0, 4);

    preorderPrint(root);

    return 0;
}