Maximum number of balloons

Hash Table String Counting

60.0% acceptance

Feb 25, 2026

1874

121

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.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn max_number_of_balloons(text: String) -> i32 {
    let mut cnt = [0i32; 26];
    for c in text.bytes() {
      cnt[(c - b'a') as usize] += 1;
    }
    // "balloon" = b,a,l,l,o,o,n -> b:1,a:1,l:2,o:2,n:1
    let b = cnt[(b'b' - b'a') as usize];
    let a = cnt[(b'a' - b'a') as usize];
    let l = cnt[(b'l' - b'a') as usize] / 2;
    let o = cnt[(b'o' - b'a') as usize] / 2;
    let n = cnt[(b'n' - b'a') as usize];
    b.min(a).min(l).min(o).min(n)
  }
}