Given a sorted array, write an algorithm to create a binary search tree with minimal height.

createMinimalBST

function createMinimalBST(array, start, end){
    if (end < start){
        return null;
    }   
    
    var mid = Math.floor( (start + end) / 2 );
    
    var node = {val: array[mid], left: null, right: null};
    node.left = createMinimalBST(array, start, mid-1);
    node.right = createMinimalBST(array, mid+1, end);
    return node;
}

// array1 = [1,2,3,4,5,6,7,8,9];
// var result = createMinimalBST(array1, 0, array1.length-1);

// console.log(result);