Maximum Number of Balloons Python Solution

Tested Python solution for LeetCode 1189 with 16 pytest cases. Generate a practice environment with lcpy.

LeetCode 1189, Easy. Topics: Hash Table, String, Counting. View on LeetCode.

Generate this problem as a practice environment: tested reference solution, 16 parametrized pytest cases, and a playground notebook:

lcpy gen -n 1189   # by problem number
lcpy gen -s maximum_number_of_balloons   # by problem name

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Problem

Given a string text, you want to use the characters of text to form as many instances of the word “balloon” as possible.

You can use each character in text at most once. Return the maximum number of instances that can be formed.

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Examples

Input: text = "nlaebolko"
Output: 1

Input: text = "loonbalxballpoon"
Output: 2

Input: text = "leetcode"
Output: 0

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Constraints

• 1 <= text.length <= 10^4
• text consists of lower case English letters only.

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Solution

Reference implementation from solution.py on GitHub, full suite in test_solution.py:

from collections import Counter


class Solution:
    # Time: O(len(text))
    # Space: O(1)
    def max_number_of_balloons(self, text: str) -> int:
        counts = Counter(text)
        return min(counts["b"], counts["a"], counts["l"] // 2, counts["o"] // 2, counts["n"])

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Complexity

Time	Space
O(len(text))	O(1)

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Tags

NeetCode All.