Renamed NQueen file, variables to NQueens, raised RangeError exception (TheAlgorithms#1162)

Author: SudhanshuSuman

Backtracking/NQueen.js renamed to Backtracking/NQueens.js

@@ -1,5 +1,8 @@
-class NQueen {
+class NQueens {
  constructor (size) {
+ if (size < 0) {
+ throw RangeError('Invalid board size')
+ }
  this.board = new Array(size).fill('.').map(() => new Array(size).fill('.'))
  this.size = size
  this.solutionCount = 0
@@ -61,4 +64,4 @@ class NQueen {
  }
 }
 
-export { NQueen }
+export { NQueens }

Backtracking/tests/NQueen.test.js

@@ -0,0 +1,19 @@
+import { NQueens } from '../NQueens'
+
+describe('NQueens', () => {
+ it('should return 2 solutions for 4x4 size board', () => {
+ const _4Queens = new NQueens(4)
+ _4Queens.solve()
+ expect(_4Queens.solutionCount).toEqual(2)
+ })
+
+ it('should return 92 solutions for 8x8 size board', () => {
+ const _8Queens = new NQueens(8)
+ _8Queens.solve()
+ expect(_8Queens.solutionCount).toEqual(92)
+ })
+
+ it('should throw RangeError for negative size board', () => {
+ expect(() => { return new NQueens(-1) }).toThrow(RangeError)
+ })
+})