Add a bunch of solutions for LeetCode problem 2626. Array Reduce Transformation (#406)

Author: miorel

workspaces/javascript-leetcode-month/problems/2626-array-reduce-transformation/solution.md

@@ -11,6 +11,172 @@
 
 ## Solutions
 
+### Using `Array.prototype.reduce`
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378766665/)
+
+```javascript []
+/**
+ * @param {number[]} arr
+ * @param {Function} fn
+ * @param {number} init
+ * @return {number}
+ */
+const reduce = (arr, fn, init) => arr.reduce(fn, init);
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378765352/)
+
+```typescript []
+const reduce = <TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult => arr.reduce(fn, init);
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378767802/)
+
+```javascript []
+/**
+ * @param {number[]} arr
+ * @param {Function} fn
+ * @param {number} init
+ * @return {number}
+ */
+const reduce = Function.prototype.call.bind(Array.prototype.reduce);
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378777231/)
+
+```typescript []
+const reduce = <TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult => [...arr].reverse().reduceRight(fn, init);
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378778477/)
+
+```typescript []
+declare global {
+  interface Array<T> {
+    toReversed(this: T[]): T[];
+  }
+
+  interface ReadonlyArray<T> {
+    toReversed(this: readonly T[]): T[];
+  }
+}
+
+const reduce = <TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult => arr.toReversed().reduceRight(fn, init);
+```
+
+### Iterative
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378776182/)
+
+```typescript []
+function reduce<TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult {
+  let res = init;
+
+  for (const element of arr) {
+    res = fn(res, element);
+  }
+
+  return res;
+}
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378776438/)
+
+```typescript []
+function reduce<TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult {
+  let res = init;
+
+  arr.forEach((element) => {
+    res = fn(res, element);
+  });
+
+  return res;
+}
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378781727/)
+
+```typescript []
+function reduce<TElement, TResult>(
+  arr: TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult {
+  let res = init;
+
+  arr.reverse();
+  while (arr.length > 0) {
+    res = fn(res, arr.pop());
+  }
+
+  return res;
+}
+```
+
+### Recursive
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378782688/)
+
+```typescript []
+const reduce = <TElement, TResult>(
+  arr: TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult =>
+  arr.length === 0 ? init : reduce(arr, fn, fn(init, arr.shift()));
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378769940/)
+
+```typescript []
+const reduce = <TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+  index: number = 0,
+): TResult =>
+  index === arr.length
+    ? init
+    : reduce(arr, fn, fn(init, arr[index]), index + 1);
+```
+
+[View Submission on LeetCode](https://leetcode.com/problems/array-reduce-transformation/submissions/1378772700/)
+
+```typescript []
+function reduce<TElement, TResult>(
+  arr: readonly TElement[],
+  fn: (accumulator: TResult, element: TElement) => TResult,
+  init: TResult,
+): TResult {
+  const doReduce = (accumulator: TResult, index: number) =>
+    index === arr.length
+      ? accumulator
+      : doReduce(fn(accumulator, arr[index]), index + 1);
+  return doReduce(init, 0);
+}
+```
+
 ## Answers to Bonus Questions
 
 > [!TIP]