Add shaker sort.

algorithms/sorting/shaker-sort/shaker-sort.js

@@ -0,0 +1,41 @@
+/**
+ * Swaps two values in an array.
+ * @param {Array} items The array containing the items.
+ * @param {int} firstIndex Index of first item to swap.
+ * @param {int} secondIndex Index of second item to swap.
+ * @return {void}
+ */
+function swap(items, firstIndex, secondIndex){
+    var temp = items[firstIndex];
+    items[firstIndex] = items[secondIndex];
+    items[secondIndex] = temp;
+}
+
+/**
+ * A shaker sort implementation in JavaScript.
+ * @param {Array} items An array of items to sort.
+ * @return {Array} The sorted array.
+ */
+function shakerSort(items) {
+	var start  = 0,
+		end = items.length - 1,
+		i;
+
+	do {
+
+		for (i = end; i > 0; i--) {
+			if (items[i-1] >= items[i]) {
+				swap(items, i, i-1);
+				start = i + 1;
+			}
+		}
+
+		for (i = 1; i <= start; i++) {
+			if (items[i-1] > items[i]) {
+				swap(items, i, i-1);
+				end = i - 1;
+			}
+		}
+
+	} while (start < end);
+}

algorithms/sorting/shell-sort/shell-sort.js

@@ -0,0 +1,39 @@
+/**
+ * Swaps two values in an array.
+ * @param {Array} items The array containing the items.
+ * @param {int} firstIndex Index of first item to swap.
+ * @param {int} secondIndex Index of second item to swap.
+ * @return {void}
+ */
+function swap(items, firstIndex, secondIndex){
+    var temp = items[firstIndex];
+    items[firstIndex] = items[secondIndex];
+    items[secondIndex] = temp;
+}
+
+/**
+ * A shell sort implementation in JavaScript.
+ * @param {Array} items An array of items to sort.
+ * @return {Array} The sorted array.
+ */
+function shellSort(items) {
+	var len = items.length
+	    step = len,
+	    i, j;
+
+	do {
+		step = Math.floor(step/2);
+		i = 0;
+		j = i + step;
+		while (j < len) {
+			if (items[i] > items[j]) {
+				swap(items, i, j);
+			}
+
+			i++;
+			j = i + step;
+		}
+	} while (step >= 1);
+
+	return items;
+}