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Java Java Data Structures - Retired Efficiency! Changing Course

Sara Worth
Sara Worth
5,225 Points

I'm totally stumped. I don't understand how to complete this challenge.

I know this sounds easy, but I can't get a handle on it.

com/example/model/Course.java
package com.example.model;

import java.util.List;

public class Course {
  private String mName;
  private List<Video> mVideos; 

  public Course(String name, List<Video> videos) {
    mName = name;
    mVideos = videos;
  }

  public String getName() {
    return mName;
  }

  public List<Video> getVideos() {
    return mVideos;
  }

}
com/example/model/Video.java
package com.example.model;

public class Video {
  private String mTitle;

  public Video(String title) {
    mTitle = title;
  }

  public String getTitle() {
    return mTitle;
  }

  public void setTitle(String title) {
    mTitle = title;
  }

}
QuickFix.java
import com.example.model.Course;
import com.example.model.Video;

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

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
    Video theBeginningBits = new Video("The Beginning Bits");
    // TODO(2):  Add the newly created video to the course videos as the second video.
    course.getVideos().add(1, theBeginningBits);
  }

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {

  }

  public Map<String, Video> videosByTitle(Course course) {
    Map<String, Video> titleToVideo = new HashMap<>();
    for (Video video : course.getVideos()) {
       titleToVideo.put(video.getTitle(), video);
    }

    return titleToVideo;
  }

}

1 Answer

I won't explain it since it is one of those answers that are obvious when you see it.

import com.example.model.Course;
import com.example.model.Video;

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

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
    Video theBeginningBits = new Video("The Beginning Bits");
    // TODO(2):  Add the newly created video to the course videos as the second video.
    course.getVideos().add(1, theBeginningBits);
  }

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
    Map<String, Video> m = videosByTitle(course);
    Video vid = m.get(oldTitle);
    vid.setTitle(newTitle);
  }

  public Map<String, Video> videosByTitle(Course course) {
    Map<String, Video> titleToVideo = new HashMap<>();
    for (Video video : course.getVideos()) {
       titleToVideo.put(video.getTitle(), video);
    }

    return titleToVideo;
  }

}
Sara Worth
Sara Worth
5,225 Points

Yes! i understand it once you wrote it out in code. I have a long way to go! thanks for your help :)