feat: Implement Insertion Sort

42.implement-Insertion-Sort.md

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+# 42. implement Insertion Sort
+Insertion Sort is a simple and intuitive comparison-based sorting algorithm. It builds the final sorted array one element at a time by repeatedly picking the next element and inserting it into its correct position among the previously sorted elements.
+
+### Problem
+
+https://bigfrontend.dev/problem/implement-Insertion-Sort
+
+#
+
+### Problem Description
+
+Even for Front-End Engineer, it is a must to understand how basic sorting algorithms work.
+
+Now you are asked to implement [Insertion Sort](https://en.wikipedia.org/wiki/Insertion_sort), which sorts an integer array in ascending order.
+
+Do it **in-place**, no need to return anything.
+
+**Follow-up**
+
+What is time cost for average / worst case ? Is it stable?
+
+#
+
+### Solution
+
+```js
+/**
+ * @param {number[]} arr
+ */
+function insertionSort(arr) {
+  for (let i = 1; i < arr.length; i++) {
+    let currentVal = arr[i];
+    let j = i - 1;
+    while (j >= 0 && currentVal < arr[j]) {
+      arr[j + 1] = arr[j];
+      j--;
+    }
+    arr[j + 1] = currentVal;
+  }
+}
+```
+
+#### Use Cases:
+
+1. **Small Data Sets**: Efficient for small datasets due to its simplicity and low overhead.
+2. **Nearly Sorted Data**: Performs very well on nearly sorted data or when the data is already sorted.
+3. **Online Sorting**: Suitable for scenarios where the list is being received in a streaming fashion, as it can sort the list as elements arrive.