LeetCode 1291. Sequential Digits

题目

class Solution {
public:
    int ans[10005];
    vector<int> sequentialDigits(int low, int high) {

        int x = 1;
        int pos=0;
        int tag=1;
        for(int i=1;i<=9;i++)
        {
            x=fun2(x);
            tag*=10;
            int xx=x;
            for(int j=1;j<=9-i;j++)
            {
                ans[pos++]=xx;

                xx=fun(xx,tag);
            }

        }

        vector<int> res;
        int tag2=0;
        for(int i=0;i<pos;i++)
        {
            if(ans[i]>=low&&ans[i]<=high)
            {
               res.push_back(ans[i]);
            }

        }
        return res;

    }

    int fun(int x,int num)
    {
        int y =x%10;

        x%=num;

        x*=10;
        x+=y+1;
        return x;
    }

    int fun2(int x)
    {
        int y = x%10;
        x*=10;
        x+=y+1;

        return x;
    }
};