Question

Python

Function Name: sign_count
Parameters: a list of integers Returns: an integer

Description: Speed signs should be posted every mile on a given street. You are given a list of 0s & 1s, where each number represents a quarter of a mile. Thus, every 4 zeroes requires a speed sign. However, a 1 indicates an intersection, and each intersection is automatically required to have a speed limit sign. A sign for each mile proceeds as usual after the intersection.

Your goal is to count the number of signs required for a given stretch of road, that is represented by a list of 0’s & 1’s.

Example Call: sign_count([1,1,1]) Expected Result: 3

Example Call: sign_count([0,0,0]) Expected Result: 0

Example Call: sign_count([0,0,0,0]) Expected Result: 1

Example Call: sign_count([0,0,0,0,0,0,0,0]) Expected Result: 2

Example Call: sign_count([0,1,1,0,0,0,0,0,0,1,0,0,1,0,0,1,0,0,0,0,0,0,0]) Expected Result: 7

Answer 1

def sign_count(lst):
    count, zero_count = 0, 0
    for num in lst:
        if num == 1:
            count += 1
            zero_count = 0
        else:
            zero_count += 1
            if zero_count == 4:
                zero_count = 0
                count += 1
    return count


print(sign_count([1, 1, 1]))
print(sign_count([0, 0, 0]))
print(sign_count([0, 0, 0, 0]))
print(sign_count([0, 0, 0, 0, 0, 0, 0, 0]))
print(sign_count([0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0]))

30127