标签:sequence log get character exp tco long style number
Find the nth digit of the infinite integer sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... Note: n is positive and will fit within the range of a 32-bit signed integer (n < 231). Example 1: Input: 3 Output: 3 Example 2: Input: 11 Output: 0 Explanation: The 11th digit of the sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... is a 0, which is part of the number 10.
1-9 : count:9 * len:1
10-99: count:90 * len:2
100-999: count:900 * len:3
1000-9999: count: 9000 * len:4
maintain a count, len, start
1 public class Solution { 2 public int findNthDigit(int n) { 3 int start = 1; 4 int len = 1; 5 long count = 9; 6 while (n > len*count) { 7 n -= len*count; 8 start *= 10; 9 len ++; 10 count *= 10; 11 } 12 start += (n-1)/len; 13 char res = Integer.toString(start).charAt((n-1)%len); 14 return Character.getNumericValue(res); 15 } 16 }
标签:sequence log get character exp tco long style number
原文地址:http://www.cnblogs.com/EdwardLiu/p/6100243.html