java ITAT往届试题
求解答：编写一个Java应用程序，对用户输入的任意一组字符如{1，3，4，7，2，1，1，5，2}，输出其中出现次数最多且数值最大的字符，并显示其出现次数

------解决方案--------------------
package com.xyj.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.Map.Entry;

public class Test5 {
public static void main(String[] args) {
BufferedReader reader = null;

try {
reader = new BufferedReader(new InputStreamReader(System.in));
String line = reader.readLine();

StringBuilder sb = new StringBuilder();
for (int i = 0; i < line.length(); i++) {
char c = line.charAt(i);
if (c <= '9' && c >= '0') {
sb.append(c).append(",");
}
}
if (sb != null && sb.length() > 0) {
sb.deleteCharAt(sb.length() - 1);
}

String[] str = sb.toString().split(",");
int[] in = new int[str.length];
for (int i = 0; i < str.length; i++) {
in[i] = Integer.parseInt(str[i]);
}

Set<Integer> hash = new HashSet<Integer>();
for (int i : in) {
hash.add(i);
}

int num = hash.size();
int[] times = new int[num];
List<Integer> list = new ArrayList<Integer>(hash);
for (int i : in) {
times[list.indexOf(i)]++;
}

Map<Integer, Integer> map = new TreeMap<Integer, Integer>(/*
new Comparator<Integer>() {
public int compare(Integer o1, Integer o2) {
return o2.compareTo(o1);
};
}*/);
for (int i = 0; i < num; i++) {
map.put(list.get(i), times[i]);
}
List<Map.Entry<Integer, Integer>> mapList = new ArrayList<Map.Entry<Integer, Integer>>(map.entrySet());
Collections.sort(mapList, new Comparator<Map.Entry<Integer, Integer>>() {
@Override
public int compare(Entry<Integer, Integer> o1,
Entry<Integer, Integer> o2) {
return o2.getValue().compareTo(o1.getValue());
}
});

Set<Entry<Integer, Integer>> set = map.entrySet();
for (Iterator<Entry<Integer, Integer>> iter = set.iterator(); iter
.hasNext();) {
Map.Entry<Integer, Integer> entry = (Entry<Integer, Integer>) iter
.next();
System.out.println("数值："+entry.getKey() + " 出现的次数为:" + entry.getValue());
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}

------解决方案--------------------

Java code

import java.util.HashMap;
import java.util.Map;


public class Test {
    public static void main(String[] args){
        int[] array = new int[]{1,3,4,7,2,1,1,5,2};
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();
        for (int i=0; i<array.length; i++){
            if (map.get(array[i]) == null){
                map.put(array[i], 1);
            } else {
                map.put(array[i], map.get(array[i]) + 1);
            }
        }
        int times = 0;
        int max = 0;
        for (Map.Entry<Integer, Integer> entry: map.entrySet()){
            if (entry.getValue() > times){
                max = entry.getKey();
                times = entry.getValue();
            } else if (entry.getValue() == times && entry.getKey() > max){
                max = entry.getKey();
            }
        }
        System.out.println("max times num: " + max + " times:" + times);
    }
}