Added README.md file for Array Reduce Transformation

2761-array-reduce-transformation/README.md

@@ -0,0 +1,62 @@
+<h2><a href="https://leetcode.com/problems/array-reduce-transformation">Array Reduce Transformation</a></h2> <img src='https://img.shields.io/badge/Difficulty-Easy-brightgreen' alt='Difficulty: Easy' /><hr><p>Given an integer array <code>nums</code>, a reducer function <code>fn</code>, and an initial value <code>init</code>, return the final result obtained by executing the <code>fn</code> function on each element of the array, sequentially, passing in the return value from the calculation on the preceding element.</p>
+
+<p>This result is achieved through the following operations: <code>val = fn(init, nums[0]), val = fn(val, nums[1]), val = fn(val, nums[2]), ...</code> until every element in the array has been processed. The ultimate value of <code>val</code> is then returned.</p>
+
+<p>If the length of the array is 0, the function should return <code>init</code>.</p>
+
+<p>Please solve it without using the built-in <code>Array.reduce</code> method.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> 
+nums = [1,2,3,4]
+fn = function sum(accum, curr) { return accum + curr; }
+init = 0
+<strong>Output:</strong> 10
+<strong>Explanation:</strong>
+initially, the value is init=0.
+(0) + nums[0] = 1
+(1) + nums[1] = 3
+(3) + nums[2] = 6
+(6) + nums[3] = 10
+The final answer is 10.
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> 
+nums = [1,2,3,4]
+fn = function sum(accum, curr) { return accum + curr * curr; }
+init = 100
+<strong>Output:</strong> 130
+<strong>Explanation:</strong>
+initially, the value is init=100.
+(100) + nums[0] * nums[0] = 101
+(101) + nums[1] * nums[1] = 105
+(105) + nums[2] * nums[2] = 114
+(114) + nums[3] * nums[3] = 130
+The final answer is 130.
+</pre>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> 
+nums = []
+fn = function sum(accum, curr) { return 0; }
+init = 25
+<strong>Output:</strong> 25
+<strong>Explanation:</strong> For empty arrays, the answer is always init.
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>0 &lt;= nums.length &lt;= 1000</code></li>
+	<li><code>0 &lt;= nums[i] &lt;= 1000</code></li>
+	<li><code>0 &lt;= init &lt;= 1000</code></li>
+</ul>