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.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
- Weekly Trends
- Python Interview Questions and Answers: Comprehensive Guide
- Scala Exercises, Practice, Solution
- Kotlin Exercises practice with solution
- MongoDB Exercises, Practice, Solution
- SQL Exercises, Practice, Solution - JOINS
- Java Basic Programming Exercises
- SQL Subqueries
- Adventureworks Database Exercises
- C# Sharp Basic Exercises
- SQL COUNT() with distinct
- JavaScript String Exercises
- JavaScript HTML Form Validation
- Java Collection Exercises
- SQL COUNT() function
- SQL Inner Join