Create merge-sort.js

Author: varun93

merge-sort.js

@@ -0,0 +1,42 @@
+const merge = (arrayA, arrayB) => {
+  let pointerA = 0,
+    pointerB = 0,
+    sortedArray = [];
+
+  while (pointerA < arrayA.length && pointerB < arrayB.length) {
+    if (arrayA[pointerA] < arrayB[pointerB]) {
+      sortedArray.push(arrayA[pointerA]);
+      pointerA++;
+    } else {
+      sortedArray.push(arrayB[pointerB]);
+      pointerB++;
+    }
+  }
+  if (pointerA < arrayA.length) {
+    sortedArray = sortedArray.concat(arrayA.slice(pointerA));
+  }
+  if (pointerB < arrayB.length) {
+    sortedArray = sortedArray.concat(arrayB.slice(pointerB));
+  }
+
+  return sortedArray;
+};
+
+const mergeSort = array => {
+  if (array.length <= 1) {
+    return array;
+  }
+
+  const left = array.slice(0, array.length / 2);
+  const right = array.slice(array.length / 2);
+
+  const leftSorted = mergeSort(left);
+  const rightSorted = mergeSort(right);
+
+  return merge(leftSorted, rightSorted);
+};
+
+const array = [22, 18, -4, 58, 7, 31, 42];
+
+const sortedArray = mergeSort(array);
+console.log(sortedArray);