Works application 2014笔试题（1）

In Figure 2, three “intervals” are overlapped at most. ? Return “3” for this case.

<Examples of test>
The class “Problem1”, which you have created in this problem, is to be tested as following.
@Test
public void testProblem1Usage() {
Problem1 p = new Problem1();
// example: Figure 1
Interval interval1 = new Interval("08:00", "12:00");
Interval interval2 = new Interval("06:00", "09:00");
Interval interval3 = new Interval("11:00", "13:30");
List<Interval> figure1 = Arrays.asList(interval1, interval2, interval3);
assertThat(p.getMaxIntervalOverlapCount(figure1), is(2));
// example: Figure 2
List<Interval> figure2 = Arrays.asList(new Interval("09:00", "12:30"),
new Interval("06:00", "09:30"), new Interval("12:00", "14:30"),
new Interval("10:00", "10:30"), new Interval("11:00", "13:30"));
assertThat(p.getMaxIntervalOverlapCount(figure2), is(3));
}

下面是个人解答，做的一般，反正目前是没有收到面试通知

package jp.co.wap.exam;


import java.util.Iterator;
import java.util.List;

import jp.co.wap.exam.lib.Interval;

//This class is tested in testProblems.testProblem1Usage();
public class Problem1 {
public int getMaxIntervalOverlapCount(List<Interval> intervals) {
// TODO: Implement this method.
	if( intervals == null || intervals.isEmpty())
return 0;
	
	for( Object interval: intervals)
		if( interval == null)
			throw new IllegalArgumentException();
	
    Iterator<Interval> it = intervals.iterator();
    int position = 0;
    int count;
    //Use a string array to record the overlap intervals.
    String positionRelation[] = new String[intervals.size()];
    for( ; it.hasNext(); ){
    	count = 1;
    	Interval curInterval = (Interval) it.next();
    	for( Object interval: intervals){
    		Interval myInterval = (Interval) interval;
    		if( myInterval.getBeginMinuteUnit() <= curInterval.getEndMinuteUnit() &&
    				myInterval.getEndMinuteUnit() >= curInterval.getBeginMinuteUnit()	)
    		if(positionRelation[position] == null)
    			positionRelation[position] = String.valueOf(count);	
    		else
    			positionRelation[position] += String.valueOf(count);	
    		count ++;
    	}
    	position ++;
    	//This can show the overlap conditions.
    	//System.out.println(positionRelation[position]);
    }
    
    //count the max overlap of the records
    int maxOverlap = 0;
    int overlapRecord;
    int countContain;
    for( int i = 0; i < positionRelation.length; i++){
    	overlapRecord = 0;
    	for ( int j = 0; j < positionRelation.length; j++){
    		//Code beneath is to validate a piece of overlap record
    		//is contained by another record
    		countContain = 0;
    		for ( int k = 0; k < positionRelation[i].length(); k++)
    		  if( positionRelation[j].contains(String.valueOf(positionRelation[i].charAt(k))))
    			   countContain ++;
    	    if(countContain == positionRelation[i].length())
    	    	overlapRecord ++;
    	}
      //If a record is fully contained by another,
      //and the count lager than length of the record
      //it means the intervals in a record are overlapped.
    	if ( overlapRecord >= positionRelation[i].length() &&
    			maxOverlap < positionRelation[i].length())
    		maxOverlap = positionRelation[i].length(); 		
    }
    			

	return maxOverlap;
}





}

package jp.co.wap.exam.lib;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* This class represents interval.
* YOU MUST NOT MODIFY THIS CLASS. (Use this as it is)
* You do not have to submit this class. (Interval class is to be provided in our scoring system.)
*/
public class Interval {
/**
* It represents Time of Hour and Minute.
*/
private static class Time {
final int hour;
final int minute;
public Time(int hour, int minute) {
this.hour = hour;
this.minute = minute;
}
@Override
public String toString() {
return String.format("%02d:%02d", hour, minute);
}
@Override
public int hashCode() {
return toString().hashCode();
}
@Override
public boolean equals(Object obj) {
if (!(obj instanceof Time)) {
return false;
}
Time other = (Time) obj;
return (this.hour == other.hour && this.minute == other.minute);
}
}
/** Initial point of interval. */
private final Time begin;
/** Terminal point of interval. */
private final Time end;
/** Create interval from begin time (string) and end time (string). */
public Interval(String begin, String end) {
this.begin = toTime(begin);
this.end = toTime(end);
}
/** Convert time format (string) to Time structure. */
private static Time toTime(String timeFormatString) {
Pattern p = Pattern.compile("(\\d?\\d):([0-5]\\d)");
Matcher m = p.matcher(timeFormatString);
if (!m.find()) {
throw new IllegalArgumentException("invalid time format.");
}
int hour = Integer.parseInt(m.group(1));
int minute = Integer.parseInt(m.group(2));
return new Time(hour, minute);
}
/** Get interval begin string.*/
public String getBegin() {
return this.begin.toString();
}
/** Get interval end string. */
public String getEnd() {
return this.end.toString();
}
/** Get interval begin hour. */
public int getBeginHour() {
return this.begin.hour;
}
/** Get interval begin minute. */
public int getBeginMinute() {
return this.begin.minute;
}
/** Get interval end hour. */
public int getEndHour() {
return this.end.hour;
}
/** Get interval end minute. */
public int getEndMinute() {
return this.end.minute;
}
/**
* Get total time (minute) from "00:00" to initial point of interval.
* For example, it returns 150 when initial point of interval is "02:30".
**/
public int getBeginMinuteUnit() {
return getBeginHour() * 60 + getBeginMinute();
}
/**
* Get total time (minute) from "00:00" to terminal point of interval.
* For example, it returns 1440 when terminal point of interval is "24:00".
**/
public int getEndMinuteUnit() {
return getEndHour() * 60 + getEndMinute();
}
/**
* Get total time on interval.
* That is, it returns getEndMinuteUnit() minus getBeginMinuteUnit().
**/
public int getIntervalMinute() {
return getEndMinuteUnit() - getBeginMinuteUnit();
}
@Override
public int hashCode() {
return toString().hashCode();
}
@Override
public boolean equals(Object obj) {
if (!(obj instanceof Interval)) {
return false;
}
Interval other = (Interval) obj;
return (this.begin.equals(other.begin) && this.end.equals(other.end));
}
@Override
public String toString() {
return String.format("[%s-%s]", begin, end);
}
}

Works application 2014笔试题（1）,,5-wow.com