NaiveStringSearch.cs

using System.Collections.Generic;

// Implements the traditional naive string matching algorithm in C# for TheAlgorithms/C-Sharp.
namespace Algorithms.Strings
{
    /// <summary>
    ///     Implements the traditional naive string matching algorithm in C#.
    /// </summary>
    public static class NaiveStringSearch
    {
        /// <summary>
        ///     NaiveSearch(Content, Pattern) will return an array containing each index of Content in which Pattern appears.
        ///     Cost:  O(n*m).
        /// </summary>
        /// <param name="content">The text body across which to search for a given pattern.</param>
        /// <param name="pattern">The pattern against which to check the given text body.</param>
        /// <returns>Array containing each index of Content in which Pattern appears.</returns>
        public static int[] NaiveSearch(string content, string pattern)
        {
            var m = pattern.Length;
            var n = content.Length;
            List<int> indices = new();
            for (var e = 0; e <= n - m; e++)
            {
                int j;
                for (j = 0; j < m; j++)
                {
                    if (content[e + j] != pattern[j])
                    {
                        break;
                    }
                }

                if (j == m)
                {
                    indices.Add(e);
                }
            }

            return indices.ToArray();
        }
    }
}