[PAT] 1054 The Dominant Color （20 分）Java

Behind the scenes in the computer's memory, color is always talked about as a series of 24 bits of information for each pixel. In an image, the color with the largest proportional area is called the dominant color. A strictly dominant color takes more than half of the total area. Now given an image of resolution M by N (for example, 800×600), you are supposed to point out the strictly dominant color.

Input Specification:

Each input file contains one test case. For each case, the first line contains 2 positive numbers: M (≤800) and N (≤600) which are the resolutions of the image. Then N lines follow, each contains M digital colors in the range [0,2​24​​). It is guaranteed that the strictly dominant color exists for each input image. All the numbers in a line are separated by a space.

Output Specification:

For each test case, simply print the dominant color in a line.

Sample Input:

5 3
0 0 255 16777215 24
24 24 0 0 24
24 0 24 24 24

Sample Output:

24

package pattest;

import java.util.*;

/**
 * @Auther: Xingzheng Wang
 * @Date: 2019/2/23 19:48
 * @Description: pattest
 * @Version: 1.0
 */
public class PAT1054 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        Map<Integer, Integer> map = new HashMap<>();
        for (int i = 0; i < n * m; i++) {
            int temp = sc.nextInt();
            if (map.containsKey(temp)) {
                int value = map.get(temp);
                value++;
                map.put(temp, value);
            } else {
                int value = 1;
                map.put(temp, value);
            }

        }
        map = sortByValue(map);
        for (Map.Entry entry : map.entrySet()) {
            System.out.println(entry.getKey());
            break;
        }
    }
    //map按照value排序
    public static <K,V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K,V> map){
        List<Map.Entry<K, V>> list = new LinkedList<>(map.entrySet());
        Collections.sort(list, (o1, o2) -> {
            int compare = (o1.getValue()).compareTo(o2.getValue());
            return -compare;
        });

        Map<K, V> result = new LinkedHashMap<K, V>();
        for (Map.Entry<K, V> entry : list) {
            result.put(entry.getKey(), entry.getValue());
        }
        return result;
    }
}