Create InsertionSort.js

Sorting/InsertionSort.js

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+
+//     Insertion sort runs in O(n²), or quadratic, time in the worst case. 
+//     This typically isn’t very effective and should not be used for large lists. 
+//     Because of insertion sort’s low hidden constant value, however, 
+//     it usually outperforms more advanced algorithms such as quick sort or merge sort on smaller lists.
+
+
+let insertionSort = (inputArr) => {
+    let length = inputArr.length;
+    for (let i = 1; i < length; i++) {
+        let key = inputArr[i];
+        let j = i - 1;
+
+        while (j >= 0 && inputArr[j] > key) {
+            inputArr[j + 1] = inputArr[j];
+            j = j - 1;
+        }
+        inputArr[j + 1] = key;
+    }
+    return inputArr;
+};