README.md

967. Numbers With Same Consecutive Differences

Return all non-negative integers of length n such that the absolute difference between every two consecutive digits is k.

Note that every number in the answer must not have leading zeros. For example, 01 has one leading zero and is invalid.

You may return the answer in any order.

Example 1:

Input: n = 3, k = 7
Output: [181,292,707,818,929]
Explanation: Note that 070 is not a valid number, because it has leading zeroes.

Example 2:

Input: n = 2, k = 1
Output: [10,12,21,23,32,34,43,45,54,56,65,67,76,78,87,89,98]

Example 3:

Input: n = 2, k = 0
Output: [11,22,33,44,55,66,77,88,99]

Example 4:

Input: n = 2, k = 2
Output: [13,20,24,31,35,42,46,53,57,64,68,75,79,86,97]

Constraints:

• 2 <= n <= 9
• 0 <= k <= 9

Solutions (Ruby)

1. Solution

# @param {Integer} n
# @param {Integer} k
# @return {Integer[]}
def nums_same_consec_diff(n, k)
  nums = (1..9).to_a

  (2..n).each do |_|
    nums_ = []

    nums.each do |x|
      y = x % 10
      nums_.push(x * 10 + y + k) if y + k < 10
      nums_.push(x * 10 + y - k) if y - k >= 0 && k != 0
    end

    nums = nums_
  end

  nums
end

Solutions (Rust)

1. Solution

impl Solution {
    pub fn nums_same_consec_diff(n: i32, k: i32) -> Vec<i32> {
        let mut nums = (1..10).collect();

        for _ in 1..n {
            let mut nums_ = vec![];

            for x in nums {
                let y = x % 10;
                if y + k < 10 {
                    nums_.push(x * 10 + y + k);
                }
                if y - k >= 0 && k != 0 {
                    nums_.push(x * 10 + y - k);
                }
            }

            nums = nums_;
        }

        nums
    }
}