Updated few Files

src/algorithms/math/bits/__test__/isEven.test.js

@@ -1,30 +1,19 @@
 import isEven from '../isEven';
 
 describe('isEven', () => {
-  it('should get if number is even or not', () => {
-    // 2 = true
-    // 3 = false
+  it('should get if number is even', () => {
     expect(isEven(2)).toBe(true);
-    expect(isEven(3)).toBe(false);
-
-    // 5 = odd
-    // 6 = even
-    expect(isEven(5)).toBe(false);
     expect(isEven(6)).toBe(true);
-
-    // 7 = odd
-    // 8 = even
-    expect(isEven(7)).toBe(false);
     expect(isEven(8)).toBe(true);
-
-    // 9 = odd
-    // 10 = even
-    expect(isEven(9)).toBe(false);
     expect(isEven(10)).toBe(true);
+    expect(isEven(12)).toBe(true);
+  });
 
-    // 11 = odd
-    // 12 = even
+  it('should get if number is odd', () => {
+    expect(isEven(3)).toBe(false);
+    expect(isEven(5)).toBe(false);
+    expect(isEven(7)).toBe(false);
+    expect(isEven(9)).toBe(false);
     expect(isEven(11)).toBe(false);
-    expect(isEven(12)).toBe(true);
   });
 });

src/algorithms/math/nth-root/README.MD

@@ -5,4 +5,4 @@ In computer science, `binary search`, also known as `half-interval search`, `log
 ![Nth Root](https://upload.wikimedia.org/wikipedia/commons/8/83/Binary_Search_Depiction.svg)
 
 ## References
-[Wikipedia](https://en.wikipedia.org/wiki/Binary_search_algorithm)
+- [Wikipedia](https://en.wikipedia.org/wiki/Binary_search_algorithm)

src/algorithms/math/nth-root/__test__/nthRoot.test.js

@@ -4,7 +4,7 @@ describe('nth Root', () => {
   it('should nth root of number', () => {
     expect(nthRoot(2, 2)).toBeCloseTo(1.414213562373095);
     expect(nthRoot(2, 3)).toBeCloseTo(1.259921049894873);
-    expect(nthRoot(2, 4)).toBeCloseTo(1.259921049894873);
+    expect(nthRoot(2, 4)).toBeCloseTo(1.189207115);
     expect(nthRoot(2, 5)).toBeCloseTo(1.148698354997035);
     expect(nthRoot(2, 6)).toBeCloseTo(1.122462048309373);
     expect(nthRoot(2, 7)).toBeCloseTo(1.104089513673812);

src/algorithms/math/nth-root/nthRoot.js

@@ -1,22 +1,32 @@
 /**
- * @param {number} number
+ * @param {number} num
  * @param {number} power
  * @return {number}
  */
 
-function difference(num, mid, p) {
-  return Math.abs(num - (mid ** p));
-}
+export default function nthRoot(num, power) {
+  const E = 0.000000001;
+  const roundToMargin = (x) => {
+    return Math.round(x / E) * E;
+  };
+
+  let guess;
+  const calculateError = () => Math.abs(num - (guess ** power));
+
+  let start = 0;
+  let end = num;
+  let error = 1;
 
-export default function nthRoot(number, p) {
-  let start = 0.0;
-  let end = number;
-  const e = 0.000000001;
-  while (true) {
-    const mid = (start + end) / 2;
-    const error = difference(number, mid, p);
-    if (error <= e) return mid;
-    if (mid ** p > number) end = mid;
-    else start = mid;
+  while (error > E) {
+    guess = (start + end) / 2;
+    error = calculateError();
+
+    if (guess ** power > num) {
+      end = guess;
+    } else {
+      start = guess;
+    }
   }
+
+  return roundToMargin(guess);
 }