1291. Sequential Digits.cpp

An integer has sequential digits if and only if each digit in the number is one more than the previous digit.

Return a sorted list of all the integers in the range [low, high] inclusive that have sequential digits.



Example 1:

Input: low = 100, high = 300
Output: [123,234]
Example 2:

Input: low = 1000, high = 13000
Output: [1234,2345,3456,4567,5678,6789,12345]


Constraints:

10 <= low <= high <= 10^9










class Solution {
public:
    vector<int> sequentialDigits(int low, int high) {
        vector<int> res;
        queue<int> q;
        for(int i=1;i<=9;i++)
            q.push(i);

        while(!q.empty()){
            int num=q.front();
            q.pop();
            if(num>=low && num<=high)
                res.push_back(num);
            if(num>high) break;
            int d=num%10;
            if(d<9){
                q.push((num*10)+d+1);
            }
        }
        return res;
    }
};