added splitwise machine coding code: test pending

.gitignore

@@ -0,0 +1,38 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.gatomalvado</groupId>
+    <artifactId>MachineCoding</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>RELEASE</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.30</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+</project>

src/main/java/com/gatomalvado/Main.java

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+package com.gatomalvado;
+
+public class Main {
+
+    public static void main(String[] args) {
+        System.out.println("Hello world!");
+    }
+}

src/main/java/com/gatomalvado/splitwise/Main.java

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+package com.gatomalvado.splitwise;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Scanner;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import com.gatomalvado.splitwise.model.Expense;
+import com.gatomalvado.splitwise.model.ExpenseType;
+import com.gatomalvado.splitwise.model.User;
+import com.gatomalvado.splitwise.orchestrator.ExpenseManager;
+
+public class Main {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        ExpenseManager expenseManager = new ExpenseManager();
+
+        // create users
+        User user1 = User.builder().userId("User1").build();
+        User user2 = User.builder().userId("User2").build();
+        User user3 = User.builder().userId("User3").build();
+        User user4 = User.builder().userId("User4").build();
+
+        // add user to the expense manager
+        expenseManager.addUser(user1);
+        expenseManager.addUser(user2);
+        expenseManager.addUser(user3);
+        expenseManager.addUser(user4);
+
+        while(true){
+            String command    = scanner.nextLine();
+            String[] commands = command.split(" ");
+            String commandType = commands[0];
+
+            switch(commandType){
+                case "SHOW":
+                    if(commands.length == 2){
+                        expenseManager.showBalanceForUser(commands[1]);
+                    } else {
+                        expenseManager.showBalance();
+                    }
+                case "EXPENSE":
+                    String userWhoPaid = commands[1];
+                    int numberOfUsers = Integer.parseInt(commands[2]);
+                    String expenseType = commands[3 + numberOfUsers];
+                    List<String> userInvolved = new ArrayList<>();
+                    for(int i=3; i< 3+numberOfUsers; i++){
+                        userInvolved.add(commands[i]);
+                    }
+                    Double amount = Double.parseDouble(commands[4+numberOfUsers]);
+                    Expense expense = null;
+                    switch(expenseType) {
+                        case "EQUAL":
+                            expense = Expense.builder()
+                                .expenseType(ExpenseType.EQUAL)
+                                .paidBy(userWhoPaid)
+                                .paidFor(userInvolved)
+                                .amount(amount)
+                                .build();
+                            expenseManager.addExpense(expense);
+                        case "EXACT":
+                            List<Double> amounts = new ArrayList<>();
+                            for(int i=5+numberOfUsers; i<commands.length; i++){
+                                amounts.add(Double.parseDouble(commands[i]));
+                            }
+                            expense = Expense.builder()
+                                .expenseType(ExpenseType.EXACT)
+                                .paidBy(userWhoPaid)
+                                .paidFor(userInvolved)
+                                .amount(amount)
+                                .exactAmount(amounts)
+                                .build();
+                            expenseManager.addExpense(expense);
+                        case "PERCENT":
+                            List<Double> percentages = new ArrayList<>();
+                            for(int i=5+numberOfUsers; i<commands.length; i++){
+                                percentages.add(Double.parseDouble(commands[i]));
+                            }
+                            expense = Expense.builder()
+                                .expenseType(ExpenseType.PERCENT)
+                                .paidBy(userWhoPaid)
+                                .paidFor(userInvolved)
+                                .amount(amount)
+                                .percentage(percentages)
+                                .build();
+                            expenseManager.addExpense(expense);
+                        default:
+                            // throw exception
+                            System.out.println("Command not supported ");
+                            break;
+                    }
+                default:
+                    break;
+            }
+        }
+    }
+
+
+
+}