add 1640

fishercoder1534 · fishercoder1534 · commit c1aa2f7da42c · 2020-11-07T20:32:34.000-08:00
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                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1640|[Check Array Formation Through Concatenation](https://leetcode.com/problems/check-array-formation-through-concatenation/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1640.java) ||Easy|Array, Sort|
 |1637|[Widest Vertical Area Between Two Points Containing No Points](https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points/)|[Javascript](./javascript/_1637.js)| | Medium | Sort |
 |1636|[Sort Array by Increasing Frequency](https://leetcode.com/problems/sort-array-by-increasing-frequency/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1636.java) ||Easy|Array, Sort|
 |1630|[Arithmetic Subarrays](https://leetcode.com/problems/arithmetic-subarrays/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1630.java) ||Medium|Sort|
diff --git a/src/main/java/com/fishercoder/solutions/_1640.java b/src/main/java/com/fishercoder/solutions/_1640.java
@@ -0,0 +1,34 @@
+package com.fishercoder.solutions;
+
+public class _1640 {
+    public static class Solution1 {
+        public boolean canFormArray(int[] arr, int[][] pieces) {
+            for (int[] piece : pieces) {
+                int first = piece[0];
+                int index = findIndex(arr, first);
+                if (index == -1) {
+                    return false;
+                }
+                int i = 0;
+                for (int j = index; i < piece.length && j < arr.length; i++, j++) {
+                    if (arr[j] != piece[i]) {
+                        return false;
+                    }
+                }
+                if (i != piece.length) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        private int findIndex(int[] arr, int key) {
+            for (int i = 0; i < arr.length; i++) {
+                if (arr[i] == key) {
+                    return i;
+                }
+            }
+            return -1;
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1640Test.java b/src/test/java/com/fishercoder/_1640Test.java
@@ -0,0 +1,39 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1640;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1640Test {
+    private static _1640.Solution1 solution1;
+    private static int[] arr;
+    private static int[][] pieces;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1640.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        arr = new int[]{85};
+        pieces = new int[][]{{85}};
+        assertEquals(true, solution1.canFormArray(arr, pieces));
+    }
+
+    @Test
+    public void test2() {
+        arr = new int[]{91, 4, 64, 78};
+        pieces = new int[][]{{78}, {4, 64}, {91}};
+        assertEquals(true, solution1.canFormArray(arr, pieces));
+    }
+
+    @Test
+    public void test3() {
+        arr = new int[]{49, 18, 16};
+        pieces = new int[][]{{16, 18, 49}};
+        assertEquals(false, solution1.canFormArray(arr, pieces));
+    }
+}
