Problem
Count how many numbers in the list are greater than zero. Zero is neither positive nor negative.
Implement count_positives(numbers).
Input
numbers: The list of integers.
Output
Return the count.
Constraints
0 ≤ length ≤ 100,000; each value fits in a 64-bit integer
Examples
Example 1
Input:
numbers = [3, -1, 0, 7, 2]
Expected output:
expected = 3Input:
std::vector<long long> numbers = {3, -1, 0, 7, 2};
Expected output:
long long expected = 3;Input:
long[] numbers = new long[] {3, -1, 0, 7, 2};
Expected output:
long expected = 3;Explanation
3, 7 and 2 are positive: 3.
Example 2
Input:
numbers = [0, 0, -5]
Expected output:
expected = 0Input:
std::vector<long long> numbers = {0, 0, -5};
Expected output:
long long expected = 0;Input:
long[] numbers = new long[] {0, 0, -5};
Expected output:
long expected = 0;Explanation
No value is above zero: 0.
How to approach it
Try on your own first, then open one hint at a time.
Hint 1
Only numbers greater than zero should be counted.
Hint 2
The task is just a filtered count over the list.
Hint 3
Do not include zero, since it is neither positive nor negative.
Expected complexity
O(n) time, O(1) extra space
References
This challenge is adapted for CodeUtility. Follow the statement and constraints above.