Description (leetcode)

A decimal number is called deci-binary if each of its digits is either 0 or 1 without any leading zeros. For example, 101 and 1100 are deci-binary, while 112 and 3001 are not.

Given a string n that represents a positive decimal integer, return the minimum number of positive deci-binary numbers needed so that they sum up to n.

Example 1:

Input: n = “32”

Output: 3

Explanation: 10 + 11 + 11 = 32

Example 2:

Input: n = “82734”

Output: 8

Example 3:

Input: n = “27346209830709182346”

Output: 9

Constraints:

  • 1 <= n.length <= 10^5
  • n consists of only digits.
  • n does not contain any leading zeros and represents a positive integer.

submission

impl Solution {
    pub fn min_partitions(n: String) -> i32 {
        // just return the max digit
        (n.bytes().max().unwrap_or(b'0') - b'0') as i32
    }
}