Finding Maximum and Minimum

Part of: Array

A Standard Algorithm. Finding the maximum or minimum value in an array is one of the standard algorithms the AP CS A exam expects you to write fluently. The idea: assume the first element is the best so far, then compare it against every other element. The Max Pattern. Key points: - Initialize max to a[0] , not to 0. If you start at 0 and all values are negative, you would wrongly return 0. - Start the loop at index 1 since index 0 is already the initial guess. - The condition a[i] max updates the running best whenever a larger value appears. The Min Pattern. Finding the minimum is identical except the comparison flips to <: Notice this version uses an enhanced for loop , which works fine because we are only reading. Comparing a[0] against itself on the first iteration is harmless. Tracking the Index of the Max. Sometimes you need where the max is, not just its value. Track an index instead: Then a[maxIndex] is the maximum and maxIndex tells you its position. What usually goes wrong. What you see What caused it How to fix it --- --- --- The maximum comes back as 0 on all-negative input max was seeded with 0 instead of a real element Seed with a[0] so the baseline is a value that ac

Challenge: Largest Element