Snail algorithm

Author: edignot

README.md

@@ -38,6 +38,9 @@ There might still be some personal comments added for my learning purposes.
 [`Test file`](https://github.com/edignot/algorithm-data-structure-practice/blob/master/src/sorting/sorting.test.js)
 
 - **All**
+    * Snail
+[`Solution`](https://github.com/edignot/algorithm-data-structure-practice/blob/master/src/snail/snail.js) 
+[`Test file`](https://github.com/edignot/algorithm-data-structure-practice/blob/master/src/snail/snail.test.js)
     * Knapsack 
 [`Solution`](https://github.com/edignot/algorithm-data-structure-practice/blob/master/src/kanpsack/knapsack.js) 
 [`Test file`](https://github.com/edignot/algorithm-data-structure-practice/blob/master/src/kanpsack/knapsack.test.js)

src/snail/snail.js

@@ -0,0 +1,45 @@
+// Problem: SnailSort is an algorithm that takes an array of equal-length sub-arrays, and then merges them into a single array in a clockwise spiral, starting from the upper-left hand corner.
+// Time complexity: 
+const arrayMatrix = [
+    [1, 2, 3, 4, 5],
+    [6, 7, 8, 9, 10],
+    [11, 12, 13, 14, 15],
+    [16, 17, 18, 19, 20],
+    [21, 22, 23, 24, 25],
+];
+
+// const arrayMatrix = [
+//   [1, 2, 3],
+//   [6, 7, 8],
+//   [11, 12, 13],
+// ];
+const snail = (arrayMatrix) => {
+    const finalArray = [];
+    while (arrayMatrix.length > 0) {
+        arrayMatrix[0].forEach((el) => finalArray.push(el));
+        arrayMatrix.splice(0, 1);
+        arrayMatrix.forEach((arr) => {
+            if (arrayMatrix.indexOf(arr) !== arrayMatrix.length - 1) {
+                finalArray.push(arr[arr.length - 1]);
+                arr.pop();
+            }
+        });
+        if (arrayMatrix[arrayMatrix.length - 1]) {
+            arrayMatrix[arrayMatrix.length - 1]
+                .reverse()
+                .forEach((el) => finalArray.push(el));
+            arrayMatrix.pop();
+        }
+        arrayMatrix.reverse();
+        arrayMatrix.forEach((arr) => {
+            if (arrayMatrix.indexOf(arr) !== arrayMatrix.length - 1) {
+                finalArray.push(arr[0]);
+                arr.shift();
+            }
+        });
+        arrayMatrix.reverse();
+    }
+    return finalArray;
+};
+
+export default snail

src/snail/snail.test.js

@@ -0,0 +1,77 @@
+import snail from "./snail";
+
+describe("Snail", () => {
+    test("Snail", () => {
+        expect(
+            snail([
+                [1, 2, 3],
+                [6, 7, 8],
+                [11, 12, 13],
+            ])
+        ).toStrictEqual([1, 2, 3, 8, 13, 12, 11, 6, 7]);
+    });
+    test("Snail", () => {
+        expect(
+            snail([
+                [1, 2, 3, 4],
+                [5, 6, 7, 8],
+                [9, 10, 11, 12],
+                [13, 14, 15, 16],
+            ])
+        ).toStrictEqual([
+            1,
+            2,
+            3,
+            4,
+            8,
+            12,
+            16,
+            15,
+            14,
+            13,
+            9,
+            5,
+            6,
+            7,
+            11,
+            10,
+        ]);
+    });
+    test("Snail", () => {
+        expect(
+            snail([
+                [1, 2, 3, 4, 5],
+                [6, 7, 8, 9, 10],
+                [11, 12, 13, 14, 15],
+                [16, 17, 18, 19, 20],
+                [21, 22, 23, 24, 25],
+            ])
+        ).toStrictEqual([
+            1,
+            2,
+            3,
+            4,
+            5,
+            10,
+            15,
+            20,
+            25,
+            24,
+            23,
+            22,
+            21,
+            16,
+            11,
+            6,
+            7,
+            8,
+            9,
+            14,
+            19,
+            18,
+            17,
+            12,
+            13,
+        ]);
+    });
+});