public void PermMissingElemSolutionTest() { var missingElement = new PermMissingElem(); //N = 4 int[] array = new int[] { 2, 3, 1, 5 }; int result = missingElement.Solve(array); Assert.AreEqual(4, result); //N = 1 array = new int[] { 2 }; result = missingElement.Solve(array); Assert.AreEqual(1, result); }