README.md

2048. Next Greater Numerically Balanced Number

An integer x is numerically balanced if for every digit d in the number x, there are exactly d occurrences of that digit in x.

Given an integer n, return the smallest numerically balanced number strictly greater than n.

Example 1:

Input: n = 1
Output: 22
Explanation:
22 is numerically balanced since:
- The digit 2 occurs 2 times.
It is also the smallest numerically balanced number strictly greater than 1.

Example 2:

Input: n = 1000
Output: 1333
Explanation:
1333 is numerically balanced since:
- The digit 1 occurs 1 time.
- The digit 3 occurs 3 times.
It is also the smallest numerically balanced number strictly greater than 1000.
Note that 1022 cannot be the answer because 0 appeared more than 0 times.

Example 3:

Input: n = 3000
Output: 3133
Explanation:
3133 is numerically balanced since:
- The digit 1 occurs 1 time.
- The digit 3 occurs 3 times.
It is also the smallest numerically balanced number strictly greater than 3000.

Constraints:

• 0 <= n <= 106

Solutions (Rust)

1. Solution

impl Solution {
    pub fn next_beautiful_number(n: i32) -> i32 {
        let mut x = n + 1;

        loop {
            let mut count = [0; 10];
            let mut y = x as usize;

            while y > 0 {
                count[y % 10] += 1;
                y /= 10;
            }

            if (0..10).all(|i| count[i] == i || count[i] == 0) {
                return x;
            }

            x += 1;
        }

        unreachable!()
    }
}