Finding a repeated integer.

(a) Given an array of \(n\) integers from 1 to \(n\) with one value repeated twice and one missing, give an algorithm that finds the missing integer, in linear time and constant extra memory. Integer overflow is not allowed.

(b) Given a read-only array of \(n\) integers, where each value from 1 to \(n-1\) occurs once and one occurs twice, give an algorithm that finds the duplicated value, in linear time and constant extra memory.

(c) Given a read-only array of \(n\) integers with values between 1 and \(n-1\), give an algorithm that finds a duplicated value, in linear time and constant extra memory.