Q1. a) Write an algorithm to find the first two largest numbers in an in array of integers. For example, given the input (2, 3, 7, −4, 5, 1), the algorithm should output 7, 5. State precisely a loop invariant for you algorithm. Prove that your loop invariant holds and hence conclude that your algorithm works. b) Analyse the algorithm to find the upper bound for run time of the above algorithm.
- (a)) Write an algorithm to find the first two largest numbers in an in array of integers. For example, given the input (2, 3, 7, −4, 5, 1), the algorithm should output 7, 5. State precisely a loop invariant for you algorithm. Prove that your loop invariant holds and hence conclude that your algorithm works. (200 words)
- (b)) Analyse the algorithm to find the upper bound for run time of the above algorithm. (200 words)
- Algorithm initializes two variables (`firstLargest`, `secondLargest`) by comparing the first two array elements.
- The algorithm iterates through the array once to find the two largest numbers.
- If `currentElement` is greater than `firstLargest`, both `firstLargest` and `secondLargest` are updated.
- If `currentElement` is greater than `secondLargest` but not `firstLargest`, only `secondLargest` is updated.
Answer: The following analysis details an algorithm to efficiently identify the two largest numbers within an array of integers, along with a rigorous proof of its correctness using loop invariants and an examination of its runtime complexity. This approach is fundamental in algorithmic design, emphasizing both correctness and efficiency for typical data processing tasks.