LeetCode 660 Remove 9 (LeetCode Weekly Contest 45)

Start from integer 1, remove any integer that contains 9 such as 9, 19, 29...

So now, you will have a new integer sequence: 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, ...

Given a positive integer n, you need to return the n-th integer after removing. Note that 1 will be the first integer.

Example 1:

Input: 9Output: 10

Hint: n will not exceed 9 x 10^8.

直接把n从十进制转换成九进制，但是要用int来表示这个九进制的数。

class Solution {public:    int newInteger(int n)     {        stack<int> s;        int cnt = 0, ret = 0;        while (n > 0)        {            int tmp = n % 9;            s.push(tmp);            ++cnt;            n = n / 9;        }        int mul = 1;        while (--cnt) mul *= 10;        while (!s.empty())        {            int tmp = s.top();            s.pop();            ret = ret + tmp * mul;            mul /= 10;        }        return ret;    }};