add 1670

fishercoder1534 · fishercoder1534 · commit 72762dd0db68 · 2021-02-03T21:53:23.000-08:00
diff --git a/README.md b/README.md
@@ -38,6 +38,7 @@ _If you like this project, please leave me a star._ &#9733;
 |1675|[Minimize Deviation in Array](https://leetcode.com/problems/minimize-deviation-in-array/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1675.java) ||Hard|Heap, Ordered Map|
 |1673|[Find the Most Competitive Subsequence](https://leetcode.com/problems/find-the-most-competitive-subsequence/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1673.java) ||Medium|Stack, Greedy|
 |1672|[Richest Customer Wealth](https://leetcode.com/problems/richest-customer-wealth/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1672.java) ||Easy|Array|
+|1670|[Design Front Middle Back Queue](https://leetcode.com/problems/design-front-middle-back-queue/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1670.java) ||Medium|Linked List, Design, Dequeu|
 |1669|[Merge In Between Linked Lists](https://leetcode.com/problems/merge-in-between-linked-lists/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1669.java) ||Medium|LinedList|
 |1668|[Maximum Repeating Substring](https://leetcode.com/problems/maximum-repeating-substring/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1668.java) ||Easy|String|
 |1664|[Ways to Make a Fair Array](https://leetcode.com/problems/ways-to-make-a-fair-array/)|[Javascript](./javascript/_1664.js) ||Medium|Greedy|
diff --git a/src/main/java/com/fishercoder/solutions/_1670.java b/src/main/java/com/fishercoder/solutions/_1670.java
@@ -0,0 +1,53 @@
+package com.fishercoder.solutions;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class _1670 {
+    public static class Solution1 {
+        /**
+         * This is a brute force approach.
+         * TODO: use two Deques to implement a solution.
+         */
+        public static class FrontMiddleBackQueue {
+            List<Integer> list;
+
+            public FrontMiddleBackQueue() {
+                list = new ArrayList<>();
+            }
+
+            public void pushFront(int val) {
+                list.add(0, val);
+            }
+
+            public void pushMiddle(int val) {
+                list.add(list.size() / 2, val);
+            }
+
+            public void pushBack(int val) {
+                list.add(val);
+            }
+
+            public int popFront() {
+                if (list.size() > 0) {
+                    return list.remove(0);
+                }
+                return -1;
+            }
+
+            public int popMiddle() {
+                if (list.size() > 0) {
+                    return list.remove(list.size() % 2 == 0 ? list.size() / 2 - 1 : list.size() / 2);
+                }
+                return -1;
+            }
+
+            public int popBack() {
+                if (list.size() > 0) {
+                    return list.remove(list.size() - 1);
+                }
+                return -1;
+            }
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1670Test.java b/src/test/java/com/fishercoder/_1670Test.java
@@ -0,0 +1,25 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1670;
+import com.fishercoder.solutions._62;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static junit.framework.Assert.assertEquals;
+
+public class _1670Test {
+    private static _1670.Solution1.FrontMiddleBackQueue solution1;
+
+    @Test
+    public void test1() {
+        solution1 = new _1670.Solution1.FrontMiddleBackQueue();
+        solution1.pushFront(1);
+        solution1.pushBack(2);
+        solution1.pushMiddle(3);
+        solution1.pushMiddle(4);
+        assertEquals(1, solution1.popFront());
+        assertEquals(3, solution1.popMiddle());
+        assertEquals(4, solution1.popMiddle());
+        assertEquals(2, solution1.popFront());
+    }
+}
