2022-09-19 update: added "Find Duplicate File in System" (#109)

Author: fartem

Diff for: README.md

@@ -540,6 +540,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 556. Next Greater Element III                                                       | [Link](https://leetcode.com/problems/next-greater-element-iii/)                                                      | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/NextGreaterElementIII.java)                                           |
 | 560. Subarray Sum Equals K                                                          | [Link](https://leetcode.com/problems/subarray-sum-equals-k/)                                                         | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/SubarraySumEqualsK.java)                                              |
 | 581. Shortest Unsorted Continuous Subarray                                          | [Link](https://leetcode.com/problems/shortest-unsorted-continuous-subarray/)                                         | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/ShortestUnsortedContinuousSubarray.java)                              |
+| 609. Find Duplicate File in System                                                  | [Link](https://leetcode.com/problems/find-duplicate-file-in-system/)                                                 | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/FindDuplicateFileInSystem.java)                                       |
 | 621. Task Scheduler                                                                 | [Link](https://leetcode.com/problems/task-scheduler/)                                                                | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/TaskScheduler.java)                                                   |
 | 622. Design Circular Queue                                                          | [Link](https://leetcode.com/problems/design-circular-queue/)                                                         | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/DesignCircularQueue.java)                                             |
 | 623. Add One Row to Tree                                                            | [Link](https://leetcode.com/problems/add-one-row-to-tree/)                                                           | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/AddOneRowToTree.java)                                                 |

Diff for: src/main/java/com/smlnskgmail/jaman/leetcodejava/medium/FindDuplicateFileInSystem.java

@@ -0,0 +1,38 @@
+package com.smlnskgmail.jaman.leetcodejava.medium;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+// https://leetcode.com/problems/find-duplicate-file-in-system/
+class FindDuplicateFileInSystem {
+
+    private final String[] input;
+
+    FindDuplicateFileInSystem(String[] input) {
+        this.input = input;
+    }
+
+    public List<List<String>> solution() {
+        Map<String, List<String>> map = new HashMap<>();
+        for (String path : input) {
+            String[] values = path.split(" ");
+            for (int i = 1; i < values.length; i++) {
+                String[] name = values[i].split("\\(");
+                name[1] = name[1].replace(")", "");
+                List<String> list = map.getOrDefault(name[1], new ArrayList<>());
+                list.add(values[0] + "/" + name[0]);
+                map.put(name[1], list);
+            }
+        }
+        List<List<String>> result = new ArrayList<>();
+        for (String key : map.keySet()) {
+            if (map.get(key).size() > 1) {
+                result.add(map.get(key));
+            }
+        }
+        return result;
+    }
+
+}

Diff for: src/test/java/com/smlnskgmail/jaman/leetcodejava/medium/FindDuplicateFileInSystemTest.java

@@ -0,0 +1,29 @@
+package com.smlnskgmail.jaman.leetcodejava.medium;
+
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class FindDuplicateFileInSystemTest {
+
+    @Test
+    public void defaultTest() {
+        assertEquals(
+                List.of(
+                        List.of("root/a/2.txt", "root/c/d/4.txt", "root/4.txt"),
+                        List.of("root/a/1.txt", "root/c/3.txt")
+                ),
+                new FindDuplicateFileInSystem(
+                        new String[]{
+                                "root/a 1.txt(abcd) 2.txt(efgh)",
+                                "root/c 3.txt(abcd)",
+                                "root/c/d 4.txt(efgh)",
+                                "root 4.txt(efgh)"
+                        }
+                ).solution()
+        );
+    }
+
+}