hackerranck/warm up/jumping on the clouds

https://www.hackerrank.com/challenges/jumping-on-the-clouds/problem?h_l=interview&playlist_slugs%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D=warmup 

 

최적화 문제인줄 걱정하지 말자. 잘 생각해보면 while문 하나로 끝낼 수 있다.

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {

    /*
     * Complete the 'jumpingOnClouds' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts INTEGER_ARRAY c as parameter.
     */

    public static int jumpingOnClouds(List<Integer> c) {
        int c_len = c.size() - 1;
        int start_idx = 0;
        int ans = 0;

        while(start_idx < c_len){
            if(start_idx+2 <= c_len && c.get(start_idx+2) == 0){
                start_idx+=2;
                ans += 1;
            }
            else if(c.get(start_idx+1) == 0){
                start_idx+=1;
                ans += 1; 
            }
        }
        return ans;
    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int n = Integer.parseInt(bufferedReader.readLine().trim());

        List<Integer> c = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
            .map(Integer::parseInt)
            .collect(toList());

        int result = Result.jumpingOnClouds(c);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}