Given an int variable n that has already been declared, write some code that repeatedly reads a value into n, until at last a number between 1 and 10 (inclusive) has been entered. assume the availability of a variable, stdin, that references a scanner object associated with standard input. that is, stdin = new scanner(system. in); is given.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?