May was a big month for new releases from Linux Academy! Take a look at what our team built recently in our blog. You can access the newest releases from our blog.
Course Of The Month
2 days, 7 hours left to enrollBecome a Premium Member and unlock a new, free course in leading technologies each month.
Solved
wordcount challenge
Posted on 2016-09-30
Hi,
I am working on below challenge.
http://codingbat.com/prob/p117630
do i need to worry about sorting like alphabetica in output?
I am working on below challenge.
http://codingbat.com/prob/p117630
The classic word-count algorithm: given an array of strings, return a Map<String, Integer> with a key for each different string, with the value the number of times that string appears in the array.
wordCount(["a", "b", "a", "c", "b"]) → {"b": 2, "c": 1, "a": 2}
wordCount(["c", "b", "a"]) → {"b": 1, "c": 1, "a": 1}
wordCount(["c", "c", "c", "c"]) → {"c": 4}
do i need to worry about sorting like alphabetica in output?
[X]
Welcome to Experts Exchange
Add your voice to the tech community where 5M+ people just like you are talking about what matters.
- Help others & share knowledge
- Earn cash & points
- Learn & ask questions
-
8
- +1
11 Comments
Active 2 days ago
Similar question as mentioned https://www.experts-exchange.com/questions/28973619/wordmultiple-challenge.html?cid=1752.
Answer is the same. :) Example results are not ordered, so need not to worry about.
Answer is the same. :) Example results are not ordered, so need not to worry about.
>> do i need to worry about sorting like alphabetica in output?
The challenge doesn't mention that, so: No.
Moreover, the're talking about returning a Map.
A Map hasn't any sorting of its keys.
The challenge doesn't mention that, so: No.
Moreover, the're talking about returning a Map.
A Map hasn't any sorting of its keys.
public Map<String, Integer> wordCount(String[] strings) {
Map<String, Integer> map=new HashMap();
for(int i=0;i<strings.length;i++){
String test=strings[i];
if(map.containsKey(test)){
int count=map.get(test);
map.put(test,count+1);
}
else{
map.put(test,1);
}
}
return map;
}
above passes all tests. any improvements or alternate approaches.
public Map < String, Integer > wordCount(String[] strings) {
Map < String, Integer > map = new SortedMap();
for (int i = 0; i < strings.length; i++) {
String test = strings[i];
if (map.containsKey(test)) {
int count = map.get(test);
map.put(test, count + 1);
} else {
map.put(test, 1);
}
}
return map;
}
why above gives below compilation error?
Compile problems:does not codingbat supports SortedMap?
Error: Map<String, Integer> map=new SortedMap();
^^^^^^^^^
Cannot instantiate the type SortedMap
see Example Code to help with compile problems
Active today
Working with SortedMap in this question is off-topic as the challenge questions requires you to use a Map.
You should look up the SortedMap API if you want to ask another question.
You should look up the SortedMap API if you want to ask another question.
SortedMap is implementation of Map interface similar to HashMap right? I thought codingbat supports that as well but looks no. Only HashMap? I will test in ecipse and see how it works
looks like no SortedMap class is there. It seems to be interface. TreeMap is only implenetation class.
https://www.tutorialspoint.com/java/java_sortedmap_interface.htm
https://www.tutorialspoint.com/java/java_sortedmap_interface.htm
package test;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
public class WordCount {
public static void main(String[] args) {
// TODO Auto-generated method stub
// wordCount(["a", "b", "a", "c", "b"]) → {"b": 2, "c": 1, "a": 2}
// Map<String, String> map = new HashMap();
// map.put("b", null);
// map.put("a", "Hi");
String[] arr = { "a", "b", "a", "c", "b" };
System.out.println("--->" + mapAB(arr));
}
/*
* private static String mapAB(String[] arr) { // TODO Auto-generated method
* stub return null; }
*/
public Map<String, Integer> wordCount(String[] strings) {
Map<String, Integer> map = new TreeMap();
for (int i = 0; i < strings.length; i++) {
String test = strings[i];
if (map.containsKey(test)) {
int count = map.get(test);
map.put(test, count + 1);
}
else {
map.put(test, 1);
}
}
return map;
}
}
above gives below error at line at line 9
The method mapAB(String[]) is undefined for the type WordCount
Not sure why and how to fix it?
package test;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
public class WordCount {
public static void main(String[] args) {
// TODO Auto-generated method stub
// wordCount(["a", "b", "a", "c", "b"]) → {"b": 2, "c": 1, "a": 2}
// Map<String, String> map = new HashMap();
// map.put("b", null);
// map.put("a", "Hi");
String[] arr = { "a", "b", "a", "c", "b" };
System.out.println("--->" + wordCount(arr));
}
/*
* private static String mapAB(String[] arr) { // TODO Auto-generated method
* stub return null; }
*/
public static Map<String, Integer> wordCount(String[] strings) {
Map<String, Integer> map = new TreeMap();
for (int i = 0; i < strings.length; i++) {
String test = strings[i];
if (map.containsKey(test)) {
int count = map.get(test);
map.put(test, count + 1);
}
else {
map.put(test, 1);
}
}
return map;
}
}
i fixed it. now i see sorted key output
--->{a=2, b=2, c=1}
package test;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
public class WordCount {
public static void main(String[] args) {
// TODO Auto-generated method stub
// wordCount(["a", "b", "a", "c", "b"]) → {"b": 2, "c": 1, "a": 2}
// Map<String, String> map = new HashMap();
// map.put("b", null);
// map.put("a", "Hi");
String[] arr = { "a","e","b", "a", "c", "b" };
System.out.println("--->" + wordCount(arr));
}
/*
* private static String mapAB(String[] arr) { // TODO Auto-generated method
* stub return null; }
*/
public static Map<String, Integer> wordCount(String[] strings) {
Map<String, Integer> map = new HashMap();
for (int i = 0; i < strings.length; i++) {
String test = strings[i];
if (map.containsKey(test)) {
int count = map.get(test);
map.put(test, count + 1);
}
else {
map.put(test, 1);
}
}
return map;
}
}
even after changing TreeMap to HashMap back again why and how it is sorting?
--->{a=2, b=2, c=1, e=1}
public Map<String, Integer> wordCount(String[] strings) {
Map<String, Integer> map=new TreeMap();
for(int i=0;i<strings.length;i++){
String test=strings[i];
if(map.containsKey(test)){
int count=map.get(test);
map.put(test,count+1);
}
else{
map.put(test,1);
}
}
return map;
}
codingbat supported TreeMap as well
Featured Post
We value your feedback.
Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!
Question has a verified solution.
If you are experiencing a similar issue, please ask a related question
In this post we will learn different types of Android Layout and some basics of an Android App.
This article will inform Clients about common and important expectations from the freelancers (Experts) who are looking at your Gig.
The viewer will learn additional member functions of the vector class. Specifically, the capacity and swap member functions will be introduced.
Suggested Courses
Course of the Month2 days, 7 hours left to enroll
719 members asked questions and received personalized solutions in the past 7 days.
Join the community of 500,000 technology professionals and ask your questions.