移除 9

/*
 * LeetCode Problem 660: Remove 9
 * 
 * Problem Statement: 
 * Start from integer 1, remove all the integers containing 9 such as 9, 19, 29...
 * Return the kth number after removing. 
 * 
 * Approach using Java Streams: 
 * 1. Create a stream of integers starting from 1. 
 * 2. Filter out numbers that contain '9' by converting to string and checking if '9' is present. 
 * 3. Limit the stream to the kth element. 
 * 4. Collect the stream to a list and return the last element of the list. 
 */
 
import java.util.stream.IntStream;
 
public class Remove9Stream {
    public int newInteger(int n) {
        return IntStream.iterate(1, i -> i + 1)
                        .filter(i -> !Integer.toString(i).contains("9"))
                        .limit(n)
                        .boxed()
                        .collect(java.util.stream.Collectors.toList())
                        .get(n - 1);
    }
}