Substring_with_Concatenation_of_All_2024

CSharp · Console

/Program.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

public class Program {
  public static void Main() {
    string val = "foobarfoobar";
	  
	Console.WriteLine(string.Join(" ", FindSubstring(val, new [] {
      "foo",
      "bar"
    })));  
    //Console.WriteLine(FindSubstring(val, new [] { "foo", "bar" }));
  }

  static IList < int > FindSubstring(string s, string[] words) {
    var list = new List < IList < string >> ();
    DoPermutation(words, 0, words.Length - 1, list);

    return TrackIndexes(s, list);
  }

  static IList < IList < string >> DoPermutation(string[] str, int start, int end, IList < IList < string >> list) {
    if (start == end) {
      list.Add(new List < string > (str));
    } else {
      for (var i = start; i <= end; i++) {
        Swap(ref str[start], ref str[i]);

        DoPermutation(str, start + 1, end, list);

        Swap(ref str[start], ref str[i]);
      }
    }

    return list;
  }

  static void Swap(ref string a, ref string b) {
    var temp = a;
    a = b;
    b = temp;
  }

  static List < int > TrackIndexes(string pattern, IList < IList < string >> aLst) {
    int count = 0;

    List < string > strings;
    List < int > indexes = new List < int > ();

    foreach(var item in aLst) {
      string str = "";

      strings = new List < string > {
        String.Concat(item)
      };

      foreach(var list in item) {
        str += list;

        if (str.Length == strings[0].Length && pattern.Contains(str)) {
          indexes.AddRange(AllIndexesOf(pattern, str));
          count += 1;
        }
      }
    }

    indexes.Sort();
    return indexes.Distinct().ToList();
  }
	
 public static int[] AllIndexesOf(string str, string substr, bool ignoreCase = false) 
 {
  if (string.IsNullOrWhiteSpace(str) || string.IsNullOrWhiteSpace(substr)) 
  {
    throw new ArgumentException("String or substring is not specified.");
  }

  var indexes = new List<int>();
  int index = 0;

  while ((index = str.IndexOf(substr, index, ignoreCase ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal)) != -1) 
  {
    indexes.Add(index++);
  }

  return indexes.ToArray();
 }
}