Leetcode 2021.3.18 (examplehub#76)

realDuYuanChao · github-actions · web-flow · commit 7c8b04db549c · 2021-03-18T14:45:51.000+08:00
* find-lucky-integer-in-an-array

* Formatted with Google Java Formatter

Co-authored-by: github-actions &lt;${GITHUB_ACTOR}@users.noreply.github.com&gt;
diff --git a/src/main/java/com/examplehub/leetcode/easy/FindLuckyIntegerInAnArray.java b/src/main/java/com/examplehub/leetcode/easy/FindLuckyIntegerInAnArray.java
@@ -0,0 +1,21 @@
+package com.examplehub.leetcode.easy;
+
+/** https://leetcode.com/problems/find-lucky-integer-in-an-array/ */
+public class FindLuckyIntegerInAnArray {
+
+  public static int solution1(int[] arr) {
+    int maxLuckyNum = -1;
+    for (int i = 0; i < arr.length; ++i) {
+      int count = 0;
+      for (int j = 0; j < arr.length; ++j) {
+        if (arr[i] == arr[j]) {
+          count++;
+        }
+      }
+      if (count > 1 && count == arr[i]) {
+        maxLuckyNum = arr[i];
+      }
+    }
+    return maxLuckyNum;
+  }
+}
diff --git a/src/test/java/com/examplehub/leetcode/easy/FindLuckyIntegerInAnArrayTest.java b/src/test/java/com/examplehub/leetcode/easy/FindLuckyIntegerInAnArrayTest.java
@@ -0,0 +1,22 @@
+package com.examplehub.leetcode.easy;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class FindLuckyIntegerInAnArrayTest {
+  @Test
+  void testSolution1() {
+    int[] arr = {2, 2, 3, 4};
+    assertEquals(2, FindLuckyIntegerInAnArray.solution1(arr));
+
+    arr = new int[] {1, 2, 2, 3, 3, 3};
+    assertEquals(3, FindLuckyIntegerInAnArray.solution1(arr));
+
+    arr = new int[] {2, 2, 2, 3, 3};
+    assertEquals(-1, FindLuckyIntegerInAnArray.solution1(arr));
+
+    arr = new int[] {-1};
+    assertEquals(-1, FindLuckyIntegerInAnArray.solution1(arr));
+  }
+}
