Solution v01

src/arrayMethodSort.js

@@ -1,12 +1,68 @@
 'use strict';
 
+const GREATER = 1;
+const EQUAL = 0;
+const LESS = -1;
+
 /**
  * Implement method Sort
  */
 function applyCustomSort() {
-  [].__proto__.sort2 = function(compareFunction) {
-    // write code here
+  [].__proto__.sort2 = function (compareFunction) {
+    if (this.length <= 1) {
+      return this;
+    }
+
+    const comparator = compareFunction ?? compareElements;
+
+    quickSort(this, 0, this.length - 1, comparator);
+
+    return this;
   };
 }
 
+function compareElements(a, b) {
+  const leftElement = String(a);
+  const rightElement = String(b);
+  let result = EQUAL;
+
+  if (leftElement > rightElement) {
+    result = GREATER;
+  }
+
+  if (leftElement < rightElement) {
+    result = LESS;
+  }
+
+  return result;
+}
+
 module.exports = applyCustomSort;
+
+function quickSort(array, left, right, callback) {
+  if (left >= right) {
+    return;
+  }
+
+  const part = partition(array, left, right, callback);
+
+  quickSort(array, left, part - 1, callback);
+  quickSort(array, part + 1, right, callback);
+}
+
+function partition(array, left, right, callback) {
+  const pivot = array[right];
+  let i = left - 1;
+
+  for (let j = left; j < right; j++) {
+    if (callback(array[j], pivot) < 0) {
+      i++;
+
+      [array[i], array[j]] = [array[j], array[i]];
+    }
+  }
+
+  [array[i + 1], array[right]] = [array[right], array[i + 1]];
+
+  return i + 1;
+}