• Home
• com.github.javadev
• leetcode-in-java
• 1.7
• source code
• Solution.java

×

Project download

Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $

You can buy this project and download/modify it how often you want.

g0301_0400.s0400_nth_digit.Solution Maven / Gradle / Ivy

package g0301_0400.s0400_nth_digit;

// #Medium #Math #Binary_Search

public class Solution {
    /*
     * 1. find the length of the number where the nth digit is from
     * 2. find the actual number where the nth digit is from
     * 3. find the nth digit and return
     */
    public int findNthDigit(int n) {
        int len = 1;
        long count = 9;
        int start = 1;
        while (n > len * count) {
            n -= len * count;
            len += 1;
            count *= 10;
            start *= 10;
        }

        start += (n - 1) / len;
        String s = Integer.toString(start);
        return Character.getNumericValue(s.charAt((n - 1) % len));
    }
}