using System;

using System.Collections.Generic;

​

public class Program

{

    static IList<int> FindAnagrams(string s, string p)

    {

        IList<int> result = new List<int>();

​

        if (s.Length < p.Length)

            return result;

​

        // Create frequency maps for strings p and the current window in s

        Dictionary<char, int> pMap = new Dictionary<char, int>();

        Dictionary<char, int> windowMap = new Dictionary<char, int>();

​

        foreach (char ch in p)

        {

            if (pMap.ContainsKey(ch))

                pMap[ch]++;

            else

                pMap[ch] = 1;

        }

​

        // Initialize the frequency map for the first window in s

        for (int i = 0; i < p.Length; i++)

        {

            char ch = s[i];

            if (windowMap.ContainsKey(ch))

                windowMap[ch]++;

            else

                windowMap[ch] = 1;

        }

​

        // Check if the first window is an anagram

        if (IsAnagram(windowMap, pMap))

            result.Add(0);

​

        // Slide the window through the rest of the string

        for (int i = p.Length; i < s.Length; i++)

        {

            // Add the current character to the window

            char addChar = s[i];

            if (windowMap.ContainsKey(addChar))

                windowMap[addChar]++;

            else

                windowMap[addChar] = 1;

​

            // Remove the leftmost character from the window

            char removeChar = s[i - p.Length];

            windowMap[removeChar]--;

​

            // Remove the character from the window map if its count becomes zero

            if (windowMap[removeChar] == 0)

                windowMap.Remove(removeChar);

​

            // Check if the current window is an anagram

            if (IsAnagram(windowMap, pMap))

                result.Add(i - p.Length + 1);

        }

​

        return result;

    }

​

    static bool IsAnagram(Dictionary<char, int> map1, Dictionary<char, int> map2)

    {

        foreach (var kvp in map2)

        {

            char key = kvp.Key;

            int count = kvp.Value;

​

            if (!map1.ContainsKey(key) || map1[key] != count)

                return false;

        }

​

        return true;

    }

​

    public static void Main()

    {

        // Example usage:

        string s = "cbaebabacd";

        string p = "abc";

        IList<int> result = FindAnagrams(s, p);

        Console.WriteLine("Indices of anagrams: []"+ string.Join(", ", result) );

    }

}

​