程式語言 - LeetCode - C++ - 400. Nth Digit



參考資訊:
https://www.cnblogs.com/grandyang/p/5891871.html

題目:


解答:

class Solution {
public:
    int findNthDigit(int n) {
        long len = 1;
        long cnt = 9;
        long start = 1;

        while (n > len * cnt) {
            n -= len * cnt;
            len += 1;
            cnt *= 10;
            start *= 10;
        }

        long num = start + (n - 1) / len;
        string s = to_string(num);
        return s[(n - 1) % len] - '0';
    }
};