add 1365

fishercoder1534 · fishercoder1534 · commit 6bd8336c066b · 2020-03-01T07:26:47.000-08:00
diff --git a/README.md b/README.md
@@ -9,6 +9,7 @@ _If you like this project, please leave me a star._ &#9733;
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
 |1367|[Linked List in Binary Tree](https://leetcode.com/problems/linked-list-in-binary-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1367.java) | |Medium||DP, Linked List, Tree
+|1365|[How Many Numbers Are Smaller Than the Current Number](https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1365.java) | |Easy||Array, HashTable
 |1362|[Closest Divisors](https://leetcode.com/problems/closest-divisors/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1362.java) | |Medium||Math
 |1361|[Validate Binary Tree Nodes](https://leetcode.com/problems/validate-binary-tree-nodes/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1361.java) | |Medium||Graph
 |1360|[Number of Days Between Two Dates](https://leetcode.com/problems/number-of-days-between-two-dates/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1360.java) | |Easy||
diff --git a/src/main/java/com/fishercoder/solutions/_1365.java b/src/main/java/com/fishercoder/solutions/_1365.java
@@ -0,0 +1,52 @@
+package com.fishercoder.solutions;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * 1365. How Many Numbers Are Smaller Than the Current Number
+ *
+ * Given the array nums, for each nums[i] find out how many numbers in the array are smaller than it.
+ * That is, for each nums[i] you have to count the number of valid j's such that j != i and nums[j] < nums[i].
+ * Return the answer in an array.
+ *
+ * Example 1:
+ * Input: nums = [8,1,2,2,3]
+ * Output: [4,0,1,1,3]
+ * Explanation:
+ * For nums[0]=8 there exist four smaller numbers than it (1, 2, 2 and 3).
+ * For nums[1]=1 does not exist any smaller number than it.
+ * For nums[2]=2 there exist one smaller number than it (1).
+ * For nums[3]=2 there exist one smaller number than it (1).
+ * For nums[4]=3 there exist three smaller numbers than it (1, 2 and 2).
+ *
+ * Example 2:
+ * Input: nums = [6,5,4,8]
+ * Output: [2,1,0,3]
+ *
+ * Example 3:
+ * Input: nums = [7,7,7,7]
+ * Output: [0,0,0,0]
+ *
+ * Constraints:
+ * 2 <= nums.length <= 500
+ * 0 <= nums[i] <= 100
+ * */
+public class _1365 {
+    public static class Solution1 {
+        public int[] smallerNumbersThanCurrent(int[] nums) {
+            int[] result = new int[nums.length];
+            int[] tmp = Arrays.copyOf(nums, nums.length);
+            Arrays.sort(tmp);
+            List<Integer> list = new ArrayList<>();
+            for (int i : tmp) {
+                list.add(i);
+            }
+            for (int i = 0; i < nums.length; i++) {
+                result[i] = list.indexOf(nums[i]);
+            }
+            return result;
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1365Test.java b/src/test/java/com/fishercoder/_1365Test.java
@@ -0,0 +1,36 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1365;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class _1365Test {
+    private static _1365.Solution1 solution1;
+    private static int[] nums;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1365.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        nums = new int[]{8, 1, 2, 2, 3};
+        assertArrayEquals(new int[]{4, 0, 1, 1, 3}, solution1.smallerNumbersThanCurrent(nums));
+    }
+
+    @Test
+    public void test2() {
+        nums = new int[]{6, 5, 4, 8};
+        assertArrayEquals(new int[]{2, 1, 0, 3}, solution1.smallerNumbersThanCurrent(nums));
+    }
+
+    @Test
+    public void test3() {
+        nums = new int[]{7, 7, 7, 7};
+        assertArrayEquals(new int[]{0, 0, 0, 0}, solution1.smallerNumbersThanCurrent(nums));
+    }
+
+}
