题目

You probably know the “like” system from Facebook and other pages. People can “like” blog posts, pictures or other items. We want to create the text that should be displayed next to such an item.

Implement a function likes :: [String] -> String, which must take in input array, containing the names of people who like an item. It must return the display text as shown in the examples:

Kata.Likes(new string[0]) => "no one likes this"
Kata.Likes(new string[] {"Peter"}) => "Peter likes this"
Kata.Likes(new string[] {"Jacob", "Alex"}) => "Jacob and Alex like this"
Kata.Likes(new string[] {"Max", "John", "Mark"}) => "Max, John and Mark like this"
Kata.Likes(new string[] {"Alex", "Jacob", "Mark", "Max"}) => "Alex, Jacob and 2 others like this"

For 4 or more names, the number in and 2 others simply increases.

代码

using System;

public static class Kata
{
  public static string Likes(string[] name)
  {
  switch(name.Length){
    case 0:return "no one likes this";
    break;

    case 1:return string.Format("{0} likes this",name[0]);
    break;

    case 2:return string.Format("{0} and {1} like this",name[0],name[1]);
    break;

    case 3:return string.Format("{0}, {1} and {2} like this",name[0],name[1],name[2]);
    break;

    default:return string.Format("{0}, {1} and {2} others like this",name[0],name[1],name.Length-2);

  }

    throw new NotImplementedException();
  }
}

解题思路

这题因为有多种情况，用switch做比较容易理清楚。