Fix the remove method for the MinHeap (trekhleb#50)

* Fix LinkedList

* Fix the prepend method for the LinkedList

* Fix the remove method for the MinHeap

Author: m-maksyutin

src/data-structures/heap/MinHeap.js

@@ -141,8 +141,8 @@ export default class MinHeap {
    */
   remove(item, customFindingComparator) {
     // Find number of items to remove.
-    const numberOfItemsToRemove = this.find(item).length;
     const customComparator = customFindingComparator || this.compare;
+    const numberOfItemsToRemove = this.find(item, customComparator).length;
 
     for (let iteration = 0; iteration < numberOfItemsToRemove; iteration += 1) {
       // We need to find item index to remove each time after removal since

src/data-structures/heap/__test__/MinHeap.test.js

@@ -1,4 +1,5 @@
 import MinHeap from '../MinHeap';
+import Comparator from '../../../utils/comparator/Comparator';
 
 describe('MinHeap', () => {
   it('should create an empty min heap', () => {
@@ -147,4 +148,25 @@ describe('MinHeap', () => {
     expect(minHeap.remove(3).toString()).toEqual('4');
     expect(minHeap.remove(4).toString()).toEqual('');
   });
+
+  it('should be possible to remove items from heap with custom finding comparator', () => {
+    const minHeap = new MinHeap();
+    minHeap.add('dddd');
+    minHeap.add('ccc');
+    minHeap.add('bb');
+    minHeap.add('a');
+
+    expect(minHeap.toString()).toBe('a,bb,ccc,dddd');
+
+    const comparator = new Comparator((a, b) => {
+      if (a.length === b.length) {
+        return 0;
+      }
+
+      return a.length < b.length ? -1 : 1;
+    });
+
+    minHeap.remove('hey', comparator);
+    expect(minHeap.toString()).toBe('a,bb,dddd');
+  });
 });