Leetcode 400. Nth Digit_综合

文章作者：Tyan
博客：noahsnail.com | CSDN | 简书

1. Description

Nth Digit

2. Solution

Version 1

class Solution {
public:int findNthDigit(int n) {int digits = 1;long base = 9;while(n > digits * base) {n -= digits * base;digits++;base *= 10;}int residual = n % digits;int quotient = n / digits;int target = base / 9 + quotient + (residual?1:0) - 1;if(residual == 0) {return target % 10;}char s = to_string(target)[residual - 1];return s - '0';}
};

Version 2

class Solution {
public:int findNthDigit(int n) {int digits = 1;long base = 9;while(n > digits * base) {n -= digits * base;digits++;base *= 10;}int residual = n % digits;int quotient = n / digits;int target = base / 9 + quotient + (residual?1:0) - 1;int count = digits - residual + 1;if(residual == 0) {return target % 10;}int result = 0;while(count) {result = target % 10;target /= 10;count--;}return result;}
};

Reference

https://leetcode.com/problems/nth-digit/description/