Count Occurrences in Sorted Array

Problem

Count how many times target appears in a sorted list using binary search.

Find the first and last occurrence with two bounded binary searches; the answer is last minus first plus one.

Return 0 when target is absent.

Hint

Count equals last index minus first index plus one.

case 1

in: [[1,1,2,2,2,3],2]

expected: 3

case 2

in: [[1,2,3],4]

expected: 0

case 3

in: [[],5]

expected: 0

case 4

in: [[5,5,5,5],5]

expected: 4

Starter codePython

def count_occurrences(nums, target):
    # Your code here
    pass

4 test cases · run your code against them in the editor