youssef3wi · August 28, 2025 19:48
diff --git a/MergePersonData.java b/MergePersonData.java
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.TreeSet;

 /**
 * You collected data about persons from multiple sources. You would like to consolidate them.
 * <p>
 * Your data is organized in a list of strings.
 * Each one corresponds to a single person, and is organized in key/value pairs.
 * Here is an example showing the format:
 * <ul>
 *     <li>{@code Name=John;Age=15;Likes=Apples}</li>
 *     <li>{@code Name=Mary;Age=16;Likes=Baked potatoes;Team=Basketball}</li>
 * </ul>
 * You have some guarantees on the input data:
 * <ul>
 *     <li>Each string will always contain the "{@code Name}" field.</li>
 *     <li>Each person can be uniquely identified by their name.
 *     If there are multiple lines with the same value of Name, they are all about the same person.</li>
 *     <li>There may be redundant information between strings,
 *     or even inside a single string, but they will never contradict each other.</li>
 *     <li>Keys and values can contain any printable ASCII characters,
 *     except {@code =} (equal sign) and {@code ;} (semicolon), which are used as separators.</li>
 *     <li>Each string does not contain any line break ({@code \r} or {@code \n})</li>
 * </ul>
 * You have to merge the data and to produce a list gathering everything about each person.
 * It should be formatted in the following way:
 * <ul>
 *     <li>All persons are sorted lexicographically by name.</li>
 *     <li>The first field for each person is "{@code Name}", then all other fields are sorted by key.</li>
 * </ul>
 * Note that these two constraints are not necessarily respected by the list you get in input.
 *
 * <h5>Constraints</h5>
 * <ul>
 *     <li>There will be at most 100 strings in the list.</li>
 *     <li>Each string has a maximum length of 1000 characters.</li>
 *     <li>Each string to output will also have a maximum length of 1000 characters.</li>
 *     <li>There are no empty names, so empty keys, no empty values.</li>
 * </ul>
 * <h5>Detailed example</h5>
 * Let's assume you receive the following strings.
 * <ul>
 *     <li>{@code Name=John;Age=15;Likes=Apples}</li>
 *     <li>{@code Name=Mary;Age=16;Likes=Baked potatoes;Team=Basketball}</li>
 *     <li>{@code Name=Adam;Age=17;Score=133;Likes=Jellied eels}</li>
 *     <li>{@code Name=John;Score=283;City=NYC}</li>
 * </ul>
 */
 public class PersonCollector {

    /**
     * @param dataStrings [[anArray]] of strings, where each string represents a person.
     * @return [[anArray]] of strings, the merged input data.
     */
    public static List<String> mergeData(List<String> dataStrings) {
        Map<String, String> entries = new TreeMap<>();
        for (String current : dataStrings) {
            String[] parts = current.split(";");
            Set<String> keys = new TreeSet<>();
            for (int idx = 1; idx < parts.length; idx++) {
                keys.add(parts[idx]);
            }

            String name = parts[0].replace("Name=", "");
            String existing = entries.get(name);
            if (existing != null) {
                parts = existing.split(";");
                for (int idx = 1; idx < parts.length; idx++) {
                    keys.add(parts[idx]);
                }
            }

            if (keys.isEmpty()) {
                current = String.format("Name=%s", name);
            } else {
                current = "Name=" + name + ";" + String.join(";", keys);
            }
            entries.put(name, current);
        }

        return new ArrayList<>(entries.values());
    }

    public static void main(String[] args) {
        String[] values = new String[]{
                "Name=John;Age=15;Likes=Apples",
                "Name=Mary;Age=16;Likes=Baked potatoes;Team=Basketball",
                "Name=Adam;Age=17;Score=133;Likes=Jellied eels",
                "Name=John;Score=283;City=NYC"};

        System.out.println("Using example: " + mergeData(Arrays.stream(values).collect(ArrayList::new, ArrayList::add, ArrayList::addAll)));
    }
 }
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.TreeMap;
	import java.util.TreeSet;

	/**
	* You collected data about persons from multiple sources. You would like to consolidate them.
	* <p>
	* Your data is organized in a list of strings.
	* Each one corresponds to a single person, and is organized in key/value pairs.
	* Here is an example showing the format:
	* <ul>
	* <li>{@code Name=John;Age=15;Likes=Apples}</li>
	* <li>{@code Name=Mary;Age=16;Likes=Baked potatoes;Team=Basketball}</li>
	* </ul>
	* You have some guarantees on the input data:
	* <ul>
	* <li>Each string will always contain the "{@code Name}" field.</li>
	* <li>Each person can be uniquely identified by their name.
	* If there are multiple lines with the same value of Name, they are all about the same person.</li>
	* <li>There may be redundant information between strings,
	* or even inside a single string, but they will never contradict each other.</li>
	* <li>Keys and values can contain any printable ASCII characters,
	* except {@code =} (equal sign) and {@code ;} (semicolon), which are used as separators.</li>
	* <li>Each string does not contain any line break ({@code \r} or {@code \n})</li>
	* </ul>
	* You have to merge the data and to produce a list gathering everything about each person.
	* It should be formatted in the following way:
	* <ul>
	* <li>All persons are sorted lexicographically by name.</li>
	* <li>The first field for each person is "{@code Name}", then all other fields are sorted by key.</li>
	* </ul>
	* Note that these two constraints are not necessarily respected by the list you get in input.
	*
	* <h5>Constraints</h5>
	* <ul>
	* <li>There will be at most 100 strings in the list.</li>
	* <li>Each string has a maximum length of 1000 characters.</li>
	* <li>Each string to output will also have a maximum length of 1000 characters.</li>
	* <li>There are no empty names, so empty keys, no empty values.</li>
	* </ul>
	* <h5>Detailed example</h5>
	* Let's assume you receive the following strings.
	* <ul>
	* <li>{@code Name=John;Age=15;Likes=Apples}</li>
	* <li>{@code Name=Mary;Age=16;Likes=Baked potatoes;Team=Basketball}</li>
	* <li>{@code Name=Adam;Age=17;Score=133;Likes=Jellied eels}</li>
	* <li>{@code Name=John;Score=283;City=NYC}</li>
	* </ul>
	*/
	public class PersonCollector {

	/**
	* @param dataStrings [[anArray]] of strings, where each string represents a person.
	* @return [[anArray]] of strings, the merged input data.
	*/
	public static List<String> mergeData(List<String> dataStrings) {
	Map<String, String> entries = new TreeMap<>();
	for (String current : dataStrings) {
	String[] parts = current.split(";");
	Set<String> keys = new TreeSet<>();
	for (int idx = 1; idx < parts.length; idx++) {
	keys.add(parts[idx]);
	}

	String name = parts[0].replace("Name=", "");
	String existing = entries.get(name);
	if (existing != null) {
	parts = existing.split(";");
	for (int idx = 1; idx < parts.length; idx++) {
	keys.add(parts[idx]);
	}
	}

	if (keys.isEmpty()) {
	current = String.format("Name=%s", name);
	} else {
	current = "Name=" + name + ";" + String.join(";", keys);
	}
	entries.put(name, current);
	}

	return new ArrayList<>(entries.values());
	}

	public static void main(String[] args) {
	String[] values = new String[]{
	"Name=John;Age=15;Likes=Apples",
	"Name=Mary;Age=16;Likes=Baked potatoes;Team=Basketball",
	"Name=Adam;Age=17;Score=133;Likes=Jellied eels",
	"Name=John;Score=283;City=NYC"};

	System.out.println("Using example: " + mergeData(Arrays.stream(values).collect(ArrayList::new, ArrayList::add, ArrayList::addAll)));
	}
	}
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