count the occurrence of letters in a string and output the letter with the highest occurrence-CodePudding

I want to count the occurence of each letter in a string and afterwards find out the letter with the highes occurrence and then return it as a char to the main method. Im just a beginner in coding so I would appreciate simple answers and solutions without adding anything from the library. Thank you for your time, I appreciate it

What I have right now:

to count the occurrence for each letter (doesnt work):

int count = 0;
for (int i = 0; i < s.Length; i  ) 
{
    if (s[0] == s[i])
    {
        count  ;
    }
}

to find out the highest number in the array:

int max = s[0];
for (int i = 0; i < s.Length; i  )
{
    if (s[i] > max)
    {
        max = s[i];
     }
}

afterwards i want to return the value as a char and output the letter

CodePudding user response：

The problem with the existing code is there is only one count variable, but there are many different letters in the string. You need a way to keep a separate count for each different letter you encounter. A Dictionary<char,int> might be a good start, or an int[] with 26 items (one for each letter in order) could do the job. There are other structures that can work, too.

Beyond that, this looks like a learning problem, where you would not be well-served by seeing more code, but rather will do better to puzzle out the rest on your own.

CodePudding user response：

You can query string with a help of Linq:

using System.Linq;

var result = s
  .GroupBy(c => c)
  .MaxBy(g => g.Count())
  .Key;

No Linq solution can use Dictionary<char, int> where Key is character and Value is its frequency.

var freq = new Dictionary<char, int>();

foreach (char c in s)
  if (freq.TryGetValue(c, out int count))
    freq[c] = count   1;
  else
    freq.Add(c, 1);

int maxCount = 0;
char result = '\0';

foreach (var pair in freq)
  if (pair.Value > maxCount) {
    maxCount = pair.Value;
    result = pair.Key; 
  }