started on unsorted array function (previous was sorted)

src/algorithms/search/twin-pointers/twinPointers.js

@@ -41,34 +41,48 @@ export function twinPointerSorted(sortedArray, seekElement, comparatorCallback)
   return [0, 0];
 }
 
-// An example of a twin pointer method on an unsorted array.
-export function twinPointerUnsorted(sortedArray, seekElement, comparatorCallback) {
+/* An example of a twin pointer method on an unsorted array. In this problem, we aim to get the heighest possible area from two numbers,
+    assuming that each number n is a rectangle of 1 width and n height. (Problem and solution taken from Leetcode #11)
+*/
+
+/**
+ *
+ * @param {*[]} unsortedArray
+ * @param {function(a, b)} [comparatorCallback]
+ * @return {number}
+ */
+
+export function twinPointerUnsorted(unsortedArray, comparatorCallback) {
     const comparator = new Comparator(comparatorCallback);
   
-    // These variables will be our pointers; since the array is sorted, we can set them to the left and rightmost elements.
+    // Again, we set our two pointers to the left and rightmost elements of the array.
     let left = 0;
-    let right = sortedArray.length - 1
-  
-    // If our left and right pointers have met then we have iterated through the entire array.
-    while (left < right) {
-      
-      /** 
-       * If our sum is less than the target then we can increase said sum but by increasing the left value; 
-       * since the array is sorted, this will always result in array[left] becoming a larger number.
-      */
-      if (comparator.lessThan(sortedArray[left] + sortedarray[right], seekElement)) {
-          left++;
-  
-      // Same concept as before, only now we decrease our sum because it's greater than the target.    
-      } else if (comparator.greaterThan(sortedArray[left] + sortedarray[right], seekElement)) {
-          right--;
-      
-      // Assuming we have found our target, return left and right since they represent the indices that our correct sum is located at.
-      } else {
-          return [left, right]
-      }
+    let right = unsortedArray.length - 1;
+
+    // We initialize two area variables; one for our current area between our two pointers and one for the highest that we'll return.
+    let area = 0;
+    let mostArea = 0;
+
+    // Functionally equivalent to the while conditional we set in the first example.
+    while (left !== right) {
+
+        // In this situation, since we don't have a specific "target" in mind we instead compare the two values at our two pointers to each other.
+        if (height[left] < height[right]) {
+            
+            // Here we simply calculate our current area and whether we need to change our highest area by comparing it with the current.
+            area = (Math.min(height[left], height[right]) * (right - left));
+            mostArea = Math.max(area, mostArea);
+            
+            /**
+             * Again, we move the left pointer forward or the right pointer backwards. You may be thinking that 
+             */
+            left++;
+        } else {
+            area = (Math.min(height[left], height[right]) * (right - left));
+            mostArea = Math.max(area, mostArea);
+            right--;
+        }
     }
-  
-    // Return [0, 0] (an impossible answer due to our while loop) if we haven't found any combination of numbers that works.
-    return [0, 0];
+
+    return mostArea
   }