# 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**except**for the number`0`itself. For example,`01`has one leading zero and is invalid, but`0`is valid.

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]
```

```
Note:1 <= N <= 9
0 <= K <= 9
```

分析

最后一个digit， lastdigit+k<10 and lastdigit-k>=0.不是用abs这里

```
class Solution:
    def numsSameConsecDiff(self, N, K):
        """
        :type N: int
        :type K: int
        :rtype: List[int]
        """

        cur = {i for i in range(10)}
        for i in range(1,N):
            temp = set()
            for j in cur:                
                lastdigit = j%10                                    
                if j > 0 and lastdigit +K<10:
                    temp.add(j*10+lastdigit +K) 
                if j > 0 and lastdigit -K>=0:
                    temp.add(j*10+lastdigit -K)    

            cur = temp

        return list(cur)
```

简化版

```
        cur = range(10)
        for i in range(1,N):
            cur = {i*10+y for i in cur for y in [i%10+K,i%10-K] if i and 0<=y<10}
        return list(cur)
```