Huawei Online Programming Questions Series-8-Consolidated Table Records

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Problem Description:

1. The question involves knowledge points.

• Key-value pair type data sorting
• MapUse in key-value pair type data merge TreeMap.

2. Solve it yourself.

• Use a priority queue to store data, sorted according to the first element
• Traverse the mailbox queue and add two consecutive elements first.

package com.chaoxiong.niuke.huawei;

import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;

/**
 * Create by tianchaoxiong on 18-5-2.
 */
public class HuaWei_8_3 {
    private int key1;
    private int key2;

    private int getKey1() {
        return key1;
    }
    public int getKey2() {
        return key2;

    }

    private HuaWei_8_3(int key1, int key2) {
        this.key1 = key1;
        this.key2 = key2;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Comparator<HuaWei_8_3>OrderIsdn = new Comparator<HuaWei_8_3>() {
            @Override
            public int compare(HuaWei_8_3 o1, HuaWei_8_3 o2) {
                int a = o1.getKey1();
                int b = o2.getKey1();
                return Integer.compare(a, b);//从大到小
            }
        };
        while (scanner.hasNextInt()){
            int N = scanner.nextInt();
            Queue<HuaWei_8_3>priorityQueue = new PriorityQueue<HuaWei_8_3>(2,OrderIsdn);
            for(int i=0;i<N;i++){
                HuaWei_8_3 huaWei_8_3 = new HuaWei_8_3(scanner.nextInt(),scanner.nextInt());
                priorityQueue.add(huaWei_8_3);
            }
            // 做一个比较打印
            int [][]intArr = new int[N][2];
            int intArrIndex = 0;
            while (priorityQueue.peek() != null) {
                HuaWei_8_3 tmp = priorityQueue.poll();
                int a1 = tmp.getKey1();
                int a2 = tmp.getKey2();
                if(intArrIndex==0){
                    intArr[intArrIndex][0] = a1;
                    intArr[intArrIndex][1] = a2;
                    intArrIndex++;
                }else {
                    if(a1==intArr[intArrIndex-1][0]){
                        intArr[intArrIndex-1][0] = a1;
                        intArr[intArrIndex-1][1] = intArr[intArrIndex-1][1]+a2;
                    }else {
                        intArr[intArrIndex][0] = a1;
                        intArr[intArrIndex][1] = a2;
                        intArrIndex++;
                    }
                }
            }
            //打印
            for(int i=0;i<intArrIndex;i++){
                System.out.println(intArr[i][0]+" "+intArr[i][1]);
            }
        }
    }
}

3. Quality answers.

mport java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

/**
 * Create by tianchaoxiong on 18-4-12.
 * // 使用map
 */
public class HuaWei_8_4 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()){
            int N = scanner.nextInt();
            Map<Integer,Integer> map= new TreeMap<Integer,Integer>();
            for(int i=0;i<N;i++){
                int key =  scanner.nextInt();
                int value =  scanner.nextInt();
                if(map.containsKey(key))
                    map.put(key,map.get(key)+value);
                else map.put(key,value);
            }
            for(Integer key:map.keySet()){
                System.out.println(key+" "+map.get(key));
            }
        }
    }
}

4. Summary of this question.

In this question, I use a priority queue to store data. I use the orderly and non-unique characteristics of the priority queue.
When traversing again, I accumulate the same key2 of key1, which is more suitable for implementation with TreeMap.