Complete The Pattern #6 - Odd Ladder
Task:
You have to write a function pattern which creates the following pattern (see examples) up to the desired number of rows.
If the Argument is 0 or a Negative Integer then it should return "" i.e. empty string.
If any even number is passed as argument then the pattern should last upto the largest odd number which is smaller than the passed even number.
Examples:
pattern(9):
1
333
55555
7777777
999999999pattern(6):
1
333
55555Note: There are no spaces in the pattern
Hint: Use \n in string to jump to next line
using System;
using System.Collections.Generic;
using System.Linq; public static class Kata
{
public static string OddLadder(int n)
{
string result = string.Empty; List<int> list = new List<int>();
for (int i = ; i <= n; i = i + )
{
list.Add(i);
}
result = string.Join("\n", list.Select(item => Selector(item))); return result;
} public static string Selector(int number)
{
string str = string.Empty;
for (int i = ; i < number; i++)
{
str = str + number.ToString();
}
return str;
}
}
Linq中的Select
//public static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector);
Func<TSource, TResult>泛型委托
//public delegate TResult Func<in T, out TResult>(T arg)
其他人的解法：
System.Linq命名空间下的Enumerable类的使用
using System;
using System.Linq; public static class Kata
{
public static string OddLadder(int n)
{
if (n <= ) return String.Empty; var oddNumbers = Enumerable.Range(, n).Where(i => i % == );
var lines = oddNumbers.Select(i => String.Join("", Enumerable.Repeat(i.ToString(), i))); return String.Join(Environment.NewLine, lines);
}
}
/// <summary>
/// Generates a sequence of integral numbers within a specified range.
/// </summary>
/// <param name="start">The value of the first integer in the sequence.</param>
/// <param name="count">The number of sequential integers to generate.</param>
/// <returns></returns>
public static IEnumerable<int> Range(int start, int count)
{ } /// <summary>
/// Generates a sequence that contains one repeated value.
/// </summary>
/// <typeparam name="TResult">The type of the value to be repeated in the result sequence.</typeparam>
/// <param name="element">The value to be repeated.</param>
/// <param name="count">The number of times to repeat the value in the generated sequence.</param>
/// <returns></returns>
public static IEnumerable<TResult> Repeat<TResult>(TResult element, int count)
{
}