codewars 题目笔记

原题：

Description:

Bob is preparing to pass IQ test. The most frequent task in this test is to find out which one of the given numbers differs from the others. Bob observed that one number usually differs from the others in evenness. Help Bob — to check his answers, he needs a program that among the given numbers finds one that is different in evenness, and return a position of this number.

找出字符串数字中不同的数字的索引

IQ.Test("2 4 7 8 10") => 3 // Third number is odd, while the rest of the numbers are even IQ.Test("1 2 1 1") => 2 // Second number is even, while the rest of the numbers are odd

public static int Test(string numbers)
{
//var numList = numbers.Split(' ').ToList();
//var evenNum = numList.Where(o => int.Parse(o) % 2 == 0).ToList();
//if (evenNum.Count == 1)
//{
// return numList.FindIndex(o => o == evenNum.First()) + 1;
//}
//else
//{
// var oddNum = numList.Where(o => !evenNum.Contains(o)).ToList();
// return numList.FindIndex(o => o == oddNum.First()) + 1;
//}
var numList = numbers.Split(' ').Select((n, i) => new { Value =int.Parse(n), Index = i });
var evenNum = numList.Where(o => o.Value % 2 == 0);
var oddNum = numList.Where(o => o.Value % 2 == 1);
return evenNum.Count() == 1 ? evenNum.First().Index + 1 : oddNum.First().Index + 1;
}

注释部分自己写的，其余部分个人感觉最优解  技术点：https://msdn.microsoft.com/zh-cn/library/bb548891.aspx      Enumerable.Select<TSource,TResult>