标签:
查找和排序
题目:输入任意(用户,成绩)序列,可以获得成绩从高到低或从低到高的排列,相同成绩
都按先录入排列在前的规则处理。
例示:
jack 70
peter 96
Tom 70
smith 67
从高到低 成绩
peter 96
jack 70
Tom 70
smith 67
从低到高
smith 67
Tom 70
jack 70
peter 96
解题思路一:
Treemap
package com.tonyluis.oj; import java.util.*; import java.util.Map.*; public class Main { public static void main(String[] args) { @SuppressWarnings("resource") Scanner in = new Scanner(System.in); TreeMap<Integer, List<String>> treeMap = new TreeMap<Integer, List<String>>(); while (in.hasNext()) { int num = in.nextInt(); int state = in.nextInt(); for (int i = 0; i < num; i++) { String name = in.next(); int score = in.nextInt(); if (treeMap.containsKey(score)) treeMap.get(score).add(name); else { List<String> list = new ArrayList<String>(); list.add(name); treeMap.put(score, list); } } List<Entry<Integer, List<String>>> list = new ArrayList<Entry<Integer, List<String>>>(treeMap.entrySet()); if (state == 0) Collections.reverse(list); for (Entry<Integer, List<String>> entry : list) for (String s : entry.getValue()) System.out.println(s + " " + entry.getKey()); treeMap.clear(); } } }
思路二:
LinkedHashMap+Comparator
import java.util.*; import java.util.Map.*; public class Main { public static void main(String[] args) { @SuppressWarnings("resource") Scanner in = new Scanner(System.in); LinkedHashMap<Integer, List<String>> hm = new LinkedHashMap<Integer, List<String>>(); while (in.hasNext()) { int num = in.nextInt(); int state = in.nextInt(); for (int i = 0; i < num; i++) { String name = in.next(); int score = in.nextInt(); if (hm.containsKey(score)) hm.get(score).add(name); else { List<String> list = new ArrayList<String>(); list.add(name); hm.put(score, list); } } List<Entry<Integer, List<String>>> list = new ArrayList<Entry<Integer, List<String>>>(hm.entrySet()); Comparator<Entry<Integer, List<String>>> c1 = new Comparator<Entry<Integer, List<String>>>() { @Override public int compare(Entry<Integer, List<String>> arg0, Entry<Integer, List<String>> arg1) { // TODO Auto-generated method stub return arg0.getKey() - arg1.getKey(); } }; Comparator<Entry<Integer, List<String>>> c2 = new Comparator<Entry<Integer, List<String>>>() { @Override public int compare(Entry<Integer, List<String>> arg0, Entry<Integer, List<String>> arg1) { // TODO Auto-generated method stub return arg1.getKey() - arg0.getKey(); } }; if (state == 1) Collections.sort(list, c1); else Collections.sort(list, c2); for (Entry<Integer, List<String>> entry : list) for (String s : entry.getValue()) System.out.println(s + " " + entry.getKey()); hm.clear(); } } }
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原文地址:http://www.cnblogs.com/tonyluis/p/5835563.html