[伯俊10816]デジタルカード2-JAVA

問題のソース

に答える

コード#コード#

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer stringTokenizer = new StringTokenizer(bufferedReader.readLine());
        int N = Integer.parseInt(stringTokenizer.nextToken());
        int[] arr = new int[N];
        stringTokenizer = new StringTokenizer(bufferedReader.readLine());
        for (int i = 0; i < N; i++) {
            arr[i] = Integer.valueOf(stringTokenizer.nextToken());
        }
        Arrays.sort(arr);

        stringTokenizer = new StringTokenizer(bufferedReader.readLine());
        int M = Integer.parseInt(stringTokenizer.nextToken());
        stringTokenizer = new StringTokenizer(bufferedReader.readLine());
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = 0; i < M; i++) {
            int key = Integer.parseInt(stringTokenizer.nextToken());
            stringBuilder.append(upperBound(arr, key) - lowerBound(arr, key)).append(" ");
        }
        System.out.println(stringBuilder);
    }

    public static int lowerBound(int[] arr, int key) {
        int lo = 0;
        int hi = arr.length;

        while (lo < hi) {
            int mid = (lo + hi) / 2;
            if (key <= arr[mid]) {
                hi = mid;
            } else {
                lo = mid + 1;
            }
        }

        return lo;
    }

    public static int upperBound(int[] arr, int key) {
        int lo = 0;
        int hi = arr.length;

        while (lo < hi) {
            int mid = (lo + hi) / 2;
            if (key < arr[mid]) {
                hi = mid;
            } else {
                lo = mid + 1;
            }
        }

        return lo;
    }
}

採点結果