lesson4

Main.java

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+package ru.gb.lesson4;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class Main {
+    public static void main(String[] args) {
+        List<String> stringList = new ArrayList<>(Arrays.asList("один", "два", "три", "два", "два", "пять"));
+
+        printWithoutDuplicates(stringList);
+        countDuplicates(stringList);
+        testPhoneBook();
+    }
+    public static void printWithoutDuplicates(List<String> input) {
+        Set<String> inputSet = new HashSet<>(input);
+        System.out.println(inputSet);
+    }
+    public static void countDuplicates(List<String> input) {
+        Set<String> inputSet = new HashSet<>(input);
+        for (String word : input) {
+            int count = 0;
+            for (String inner : input) {
+                if (word.equals(inner)) {
+                    count++;
+                }
+            }
+            System.out.printf("%s: %d\n", word, count);
+        }
+    }
+    public static void testPhoneBook() {
+        PhoneBook.add("Ivanov", "+8 495 123");
+        PhoneBook.add("Petrov", "+8 495 234");
+        PhoneBook.add("Sidorov", "+8 495 345");
+        PhoneBook.add("Ivanov", "+8 495 456");
+        PhoneBook.add("Chernov", "+8 495 567");
+        PhoneBook.add("Popov", "+8 495 678");
+
+        PhoneBook.get("Ivanov");
+    }
+}

PhoneBook.java

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+package ru.gb.lesson4;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Arrays;
+
+
+public class PhoneBook {
+    private static final Map<String, List<String>> phoneBook = new HashMap<>();
+
+    public static void add(String name, String... phonesToAdd) {
+        if(phoneBook.get(name) != null) {
+            List<String> phones = new ArrayList<>(phoneBook.get(name));
+            phones.addAll(Arrays.asList(phonesToAdd));
+           phoneBook.put(name, phones);
+        } else {
+            phoneBook.put(name, Arrays.asList(phonesToAdd));
+        }
+    }
+    public static void get(String name) {
+        System.out.printf("%s: %s\n", name, phoneBook.get(name));
+    }
+}