문제 난이도 : Easy

문제 유형 : Data Structures - Arrays

문제 설명 간략 :

배열을 주어진 int만큼 왼쪽으로 돌려라.

idea

돌린 위치부터 담고 나머지를 처음부터 순서대로 담는다.

제약사항

• 1 <= n <= 10^5
• 1 <= d <= n
• 1 <= a[i] <= 10^6

자바 풀이

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 'rotateLeft' function below.
     *
     * The function is expected to return an INTEGER_ARRAY.
     * The function accepts following parameters:
     *  1. INTEGER d
     *  2. INTEGER_ARRAY arr
     */

    public static List<Integer> rotateLeft(int d, List<Integer> arr) {
        List<Integer> rotated = new ArrayList<Integer>();

        for(int i = d; i < arr.size(); i++) {
            rotated.add(arr.get(i));
        }

        for(int i = 0; i < d; i++) {
            rotated.add(arr.get(i));
        }

        return rotated;

    }

}

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")));

        String[] firstMultipleInput = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");

        int n = Integer.parseInt(firstMultipleInput[0]);

        int d = Integer.parseInt(firstMultipleInput[1]);

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

        List<Integer> result = Result.rotateLeft(d, arr);

        bufferedWriter.write(
                result.stream()
                        .map(Object::toString)
                        .collect(joining(" "))
                        + "\n"
        );

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

출처

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