add 1346

fishercoder1534 · fishercoder1534 · commit d80c6f03d583 · 2020-02-08T21:25:38.000-08:00
diff --git a/README.md b/README.md
@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ &#9733;
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1346|[Check If N and Its Double Exist](https://leetcode.com/problems/check-if-n-and-its-double-exist/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1346.java) | |Easy|Array|
 |1345|[Jump Game IV](https://leetcode.com/problems/jump-game-iv/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1345.java) | |Hard|BFS|
 |1344|[Angle Between Hands of a Clock](https://leetcode.com/problems/angle-between-hands-of-a-clock/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1344.java) | |Medium|Math|
 |1343|[Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold](https://leetcode.com/problems/number-of-sub-arrays-of-size-k-and-average-greater-than-or-equal-to-threshold/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1343.java) | |Medium|Array|
diff --git a/src/main/java/com/fishercoder/solutions/_1346.java b/src/main/java/com/fishercoder/solutions/_1346.java
@@ -0,0 +1,46 @@
+package com.fishercoder.solutions;
+
+/**
+ * 1346. Check If N and Its Double Exist
+ *
+ * Given an array arr of integers, check if there exists two integers N and M such that N is the double of M ( i.e. N = 2 * M).
+ *
+ * More formally check if there exists two indices i and j such that :
+ *
+ * i != j
+ * 0 <= i, j < arr.length
+ * arr[i] == 2 * arr[j]
+ *
+ * Example 1:
+ * Input: arr = [10,2,5,3]
+ * Output: true
+ * Explanation: N = 10 is the double of M = 5,that is, 10 = 2 * 5.
+ *
+ * Example 2:
+ * Input: arr = [7,1,14,11]
+ * Output: true
+ * Explanation: N = 14 is the double of M = 7,that is, 14 = 2 * 7.
+ *
+ * Example 3:
+ * Input: arr = [3,1,7,11]
+ * Output: false
+ * Explanation: In this case does not exist N and M, such that N = 2 * M.
+ *
+ * Constraints:
+ * 2 <= arr.length <= 500
+ * -10^3 <= arr[i] <= 10^3
+ * */
+public class _1346 {
+    public static class Solution1 {
+        public boolean checkIfExist(int[] arr) {
+            for (int i = 0; i < arr.length; i++) {
+                for (int j = 0; j < arr.length; j++) {
+                    if (i != j && (arr[i] * 2 == arr[j] || arr[i] == arr[j] * 2)) {
+                        return true;
+                    }
+                }
+            }
+            return false;
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1346Test.java b/src/test/java/com/fishercoder/_1346Test.java
@@ -0,0 +1,36 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1346;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1346Test {
+    private static _1346.Solution1 solution1;
+    private static int[] arr;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1346.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        arr = new int[]{10, 2, 5, 3};
+        assertEquals(true, solution1.checkIfExist(arr));
+    }
+
+    @Test
+    public void test2() {
+        arr = new int[]{7, 1, 14, 11};
+        assertEquals(true, solution1.checkIfExist(arr));
+    }
+
+    @Test
+    public void test3() {
+        arr = new int[]{3, 1, 7, 11};
+        assertEquals(true, solution1.checkIfExist(arr));
+    }
+
+}
