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 textat most once. Return the maximum number of instances that can be formed.
Example 1:
Input: text = "nlaebolko"
Output: 1
Example 2:
Input: text = "loonbalxballpoon"
Output: 2
Example 3:
Input: text = "leetcode"
Output: 0
Constraints:
1 <= text.length <= 104
text consists of lower case English letters only.
Solutions
Solution 1: Counting
We count the frequency of each letter in the string text, and then divide the frequency of the letters 'o' and 'l' by 2, because the word balloon contains the letters 'o' and 'l' twice.
Next, we traverse each letter in the word balon, and find the minimum frequency of each letter in the string text. This minimum frequency is the maximum number of times the word balloon can appear in the string text.
The time complexity is $O(n)$, and the space complexity is $O(C)$. Here, $n$ is the length of the string text, and $C$ is the size of the character set. In this problem, $C = 26$.