problem

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 <= 105
  • 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
    }
}