第 N 位数字

// Java Stream solution
// The problem can also be solved using Java Streams, though it may not be as straightforward as the loop approach.
// Approach:
// 1. We generate the numbers and concatenate them as strings.
// 2. Using Stream, we find the nth digit.
 
import java.util.stream.Stream;
 
public class Solution {
    public int findNthDigit(int n) {
        return Stream.iterate(1, i -> i + 1)
                .map(Object::toString)
                .flatMapToInt(String::chars)
                .map(c -> c - '0')
                .skip(n - 1)
                .findFirst()
                .getAsInt();
    }
}