Write a function that takes an array of integers and checks for duplicate values in any contiguous window of size N.

To efficiently check for duplicates within a sliding window of size N in an array, you can employ a set to store elements currently within the window. Iterate through the array, adding each element to the set. Before adding, check if the element already exists in the set; if it does, a duplicate is found within the window. To maintain the window size, remove the element that falls out of the window (i.e., the element N positions behind the current one) from the set before adding the new element. This approach ensures that the set always contains elements from the current window of size N, allowing for O(1) average time complexity for lookups and removals.