Restyle Quick sort in js (#50)

* Quick sort in js

* Added test case for quick sort

* Restyled by clang-format

* Restyled by prettier

Co-authored-by: kheenvraj <[email protected]>
Co-authored-by: Restyled.io <[email protected]>

Sorting/quick_sort/quick_sort.js

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+// Quick sort algorithm in JS.
+/**
+   @param {Array} arr Input array.
+    @param {Number} left Input array.
+    @param {Number} right Input array.
+    @return {Array} Sorted array.
+*/
+
+module.exports = {
+  quickSort: (arr, left, right) => {
+    let pivot, partitionIndex;
+
+    if (left < right) {
+      pivot = right;
+      partitionIndex = partition(arr, pivot, left, right);
+
+      // sort left and right
+      quickSort(arr, left, partitionIndex - 1);
+      quickSort(arr, partitionIndex + 1, right);
+    }
+    return arr;
+  },
+};
+
+/**
+ * This function  keep move all the items smaller than the pivot value to the
+ * left and larger than pivot value to the right
+ */
+function partition(arr, pivot, left, right) {
+  let pivotValue = arr[pivot],
+    partitionIndex = left;
+
+  for (let i = left; i < right; i++) {
+    if (arr[i] < pivotValue) {
+      swap(arr, i, partitionIndex);
+      partitionIndex++;
+    }
+  }
+  swap(arr, right, partitionIndex);
+  return partitionIndex;
+}
+
+/** This function to swap values of the array. */
+function swap(arr, i, j) {
+  let temp = arr[i];
+  arr[i] = arr[j];
+  arr[j] = temp;
+}

Sorting/quick_sort/quick_sort.test.js

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+// Test case of quick sort function.
+const quick_sort_test = require("./quick_sort.js");
+
+const input = [11, 8, 14, 3, 6, 2, 7];
+const left = 0;
+const right = 6;
+const sorted = quick_sort_test.quickSort(input, left, right);
+console.log("Quick sort output: ", sorted);