add solution for 1086

fishercoder1534 · fishercoder1534 · commit 694eb0f80728 · 2019-11-28T18:54:59.000-08:00
diff --git a/README.md b/README.md
@@ -44,6 +44,7 @@ Your ideas/fixes/algorithms are more than welcome!
 |1170|[Compare Strings by Frequency of the Smallest Character](https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1170.java) | | | |Easy||
 |1119|[Remove Vowels from a String](https://leetcode.com/problems/remove-vowels-from-a-string/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1119.java) | | | [:tv:](https://www.youtube.com/watch?v=6KCBrIWEauw)|Easy||
 |1089|[Duplicate Zeros](https://leetcode.com/problems/duplicate-zeros/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1089.java) | O(n^2) | O(1) | |Easy||
+|1086|[High Five](https://leetcode.com/problems/high-five/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1086.java) | | | |Easy||
 |1085|[Sum of Digits in the Minimum Number](https://leetcode.com/problems/sum-of-digits-in-the-minimum-number/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1085.java) | | | |Easy||
 |1079|[Letter Tile Possibilities](https://leetcode.com/problems/letter-tile-possibilities/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1079.java) | O(1) | O(1) | |Medium||
 |1078|[Occurrences After Bigram](https://leetcode.com/problems/occurrences-after-bigram/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1078.java) | O(n) | O(1) | |Easy||
diff --git a/src/main/java/com/fishercoder/solutions/_1086.java b/src/main/java/com/fishercoder/solutions/_1086.java
@@ -0,0 +1,58 @@
+package com.fishercoder.solutions;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * 1086. High Five
+ *
+ * Given a list of scores of different students, return the average score of each student's top five scores in the order of each student's id.
+ * Each entry items[i] has items[i][0] the student's id, and items[i][1] the student's score.
+ * The average score is calculated using integer division.
+ *
+ * Example 1:
+ * Input: [[1,91],[1,92],[2,93],[2,97],[1,60],[2,77],[1,65],[1,87],[1,100],[2,100],[2,76]]
+ * Output: [[1,87],[2,88]]
+ * Explanation:
+ * The average of the student with id = 1 is 87.
+ * The average of the student with id = 2 is 88.6. But with integer division their average converts to 88.
+ *
+ * Note:
+ * 1 <= items.length <= 1000
+ * items[i].length == 2
+ * The IDs of the students is between 1 to 1000
+ * The score of the students is between 1 to 100
+ * For each student, there are at least 5 scores
+ * */
+public class _1086 {
+    public static class Solution1 {
+        public int[][] highFive(int[][] items) {
+            TreeMap<Integer, List<Integer>> map = new TreeMap<>();
+            for (int[] studentToScore : items) {
+                if (map.containsKey(studentToScore[0])) {
+                    map.get(studentToScore[0]).add(studentToScore[1]);
+                } else {
+                    List<Integer> list = new ArrayList<>();
+                    list.add(studentToScore[1]);
+                    map.put(studentToScore[0], list);
+                }
+            }
+            int[][] result = new int[map.size()][2];
+            for (int id : map.keySet()) {
+                List<Integer> scores = map.get(id);
+                Collections.sort(scores);
+                int sum = 0;
+                for (int i = scores.size() - 1; i >= scores.size() - 5 && i >= 0; i--) {
+                    sum += scores.get(i);
+                }
+                result[id - 1][0] = id;
+                result[id - 1][1] = sum / 5;
+            }
+            return result;
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1086Test.java b/src/test/java/com/fishercoder/_1086Test.java
@@ -0,0 +1,39 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1086;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class _1086Test {
+    private static _1086.Solution1 solution1;
+    private static int[][] items;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1086.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        items = new int[][]{
+                {1, 91},
+                {1, 92},
+                {2, 93},
+                {2, 97},
+                {1, 60},
+                {2, 77},
+                {1, 65},
+                {1, 87},
+                {1, 100},
+                {2, 100},
+                {2, 76}
+        };
+        assertArrayEquals(new int[][]{
+                {1, 87},
+                {2, 88}
+        }, solution1.highFive(items));
+    }
+
+}
