Python: Find the h-index, the largest positive number h such that h occurs in the sequence at least h times

Python Programming Puzzles: Exercise-49 with Solution

Write a Python program to find the h-index, the largest positive number h such that h occurs in the sequence at least h times. If there is no such positive number return h = -1.

Input:
[1, 2, 2, 3, 3, 4, 4, 4, 4]
Output:
4

Input:
[1, 2, 2, 3, 4, 5, 6]
Output:
2

Input:
[3, 1, 4, 17, 5, 17, 2, 1, 41, 32, 2, 5, 5, 5, 5]
Output:
5

Pictorial Presentation:

Sample Solution:

Python Code:

#License: https://bit.ly/3oLErEI

def test(nums):
    return max([-1] + [i for i in nums if i > 0 and nums.count(i) >= i])

nums =  [1, 2, 2, 3, 3, 4, 4, 4, 4]
print("Original list of numbers:")
print(nums)
print("h-index, the largest positive number h such that h occurs in the said sequence at least h times:")
print(test(nums))
nums =  [1,2,2,3,4,5,6]
print("\nOriginal list of numbers:")
print(nums)
print("h-index, the largest positive number h such that h occurs in the said sequence at least h times:")
print(test(nums))
nums = [3, 1, 4, 17, 5, 17, 2, 1, 41, 32, 2, 5, 5, 5, 5]
print("\nOriginal list of numbers:")
print(nums)
print("h-index, the largest positive number h such that h occurs in the said sequence at least h times:")
print(test(nums))

Sample Output:

Original list of numbers:
[1, 2, 2, 3, 3, 4, 4, 4, 4]
h-index, the largest positive number h such that h occurs in the said sequence at least h times:
4

Original list of numbers:
[1, 2, 2, 3, 4, 5, 6]
h-index, the largest positive number h such that h occurs in the said sequence at least h times:
2

Original list of numbers:
[3, 1, 4, 17, 5, 17, 2, 1, 41, 32, 2, 5, 5, 5, 5]
h-index, the largest positive number h such that h occurs in the said sequence at least h times:
5

Flowchart:

Python Code Editor :

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Find the indices of two entries that show that the list is not in increasing order.
Next: Find the even-length words and sort them by length.