# Title: Linear search
# Heading: Python Program for Linear Search
# Level: beginner
# Tags: searching, linear search, sequential search, list
# Time: O(n)
# Space: O(1)
# About: Finds a value in a list by checking each item in turn, from the first to the last, until one matches.

def linear_search(items, target):
    """The index of target in items, or -1."""
    for index, item in enumerate(items):
        if item == target:
            return index
    return -1


numbers = [42, 7, 19, 3, 88, 25, 61]
print("Index of 88:", linear_search(numbers, 88))
print("Index of 50:", linear_search(numbers, 50))