[英]Count All Character Occurrences in a String C#
在 C# 中動態計算每個字符出現的最佳方法是什么?
給予
string sample = "Foe Doe";
它應該輸出類似
f = 1
o = 2
e = 2
d = 1
計算單個字符很容易,但在我的考試中這有點棘手,我只能想象一個獲取所有唯一字符的解決方案 -> 然后將其存儲在一個集合(最好是一個數組)中,然后為該數組嵌套一個 for 循環和字符串。
還有比這更好的解決方案嗎?
使用 LINQ
sample.GroupBy(c => c).Select(c => new { Char = c.Key, Count = c.Count()});
您可以使用類似於字典的Lookup<k,e>
:
var charLookup = sample.Where(char.IsLetterOrDigit).ToLookup(c => c); // IsLetterOrDigit to exclude the space
foreach (var c in charLookup)
Console.WriteLine("Char:{0} Count:{1}", c.Key, charLookup[c.Key].Count());
您可以為此使用 Linq:
sample.GroupBy(x => x).Select(x => $"{x.Key} = {x.Count()}").
並調整您可以刪除空字符,使大小寫不敏感等。
str.ToLower().GroupBy(x => x).Where(x => x.Key != ' ').Select(x => $"{x.Key} = {x.Count()}")
等等..
class Program
{
static void Main(string[] args)
{
const string inputstring = "Hello World";
var count = 0;
var charGroups = (from s in inputstring
group s by s into g
select new
{
c = g.Key,
count = g.Count(),
}).OrderBy(c => c.count);
foreach (var x in charGroups)
{
Console.WriteLine(x.c + ": " + x.count);
count = x.count;
}
Console.Read();
}
}
由於string
實現了IEnumerable<char>
,您可以使用 Linq .Where() 和 .GroupBy() 擴展來計算字母並消除空格。
string sample = "Foe Doe";
var letterCounter = sample.Where(char.IsLetterOrDigit)
.GroupBy(char.ToLower)
.Select(counter => new { Letter = counter.Key, Counter = counter.Count() });
foreach (var counter in letterCounter)
{
Console.WriteLine(String.Format("{0} = {1}", counter.Letter, counter.Counter));
}
string str;
int i, cnt;
Console.WriteLine("Enter a sentence");
str = Console.ReadLine();
char ch;
for (ch = (char)65; ch <= 90; ch++)
{
cnt = 0;
for ( i = 0; i < str.Length; i++)
{
if (ch == str[i] || (ch + 32) == str[i])
{
cnt++;
}
}
if (cnt > 0)
{
Console.WriteLine(ch + "=" + cnt);
}
}
Console.ReadLine();
string str = "Orasscleee";
Dictionary<char,int> c=new Dictionary<char, int>();
foreach (var cc in str)
{
char c1 = char.ToUpper(cc);
try
{
c.Add(c1,1);
}
catch (Exception e)
{
c[c1] = c[c1] + 1;
}
}
foreach (var c1 in c)
{
Console.WriteLine($"{c1.Key}:{c1.Value}");
}
string new_string= String.Concat(s.OrderBy(c => c)); //for sorting string
for (int i = 0; i < new_string.Length; i++)
{
int count = 0;
for (int j = i; j < new_string.Length; j++)
{
if (new_string[i] == new_string[j])
{
count++;
}
else
{
if (count == 0)
{ count = 1; }
break;
}
}
Console.WriteLine("count for "+new_string[i]+"is: "+count);
new_string=new_string.Remove(0, count);
i = 0;
}
Console.ReadKey();
}
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