Multi String Search

string bigstring = "this is a big string";
string[] smallstrings = { "this", "yo", "is", "a", "bigger", "string", "kappa" };

List result = MultistringSearch(bigstring, smallstrings);
foreach (bool b in result)
{
    Console.WriteLine(b);
}

//Expected output: [true, false, true, true, false, true, false]
      

Solution 1.

public static List MultistringSearch(string bigstring, string[] smallstrings)
{
    List result = new List();
    foreach (string smalString in smallstrings)
    {
        result.Add(isContain(smalString, bigstring));
    }
    return result;
}


public static bool isContain(string smallString, string bigString)
{
    for (int i = 0; i <= bigString.Length - smallString.Length; i++)
    {
        int j;
        for (j = 0; j < smallString.Length; j++)
        {
            if (bigString[i + j] != smallString[j])
            {
                break;
            }
        }
        if (j == smallString.Length)
        {
            return true;
        }
    }
    return false;
}
      

Solution 2:

public static bool IsContain(string smallString, string bigString)
{
    for (int i = 0; i < bigString.Length; i++)
    {
        if (i + smallString.Length > bigString.Length)
        {
            break;
        }

        if(IsContain(smallString, bigString, i))
        {
            return true;
        }
    }
    return false;
}

private static bool IsContain(string smallString, string bigString, int startIdx)
{
    int leftBigidx = startIdx;
    int rightBigIdx = startIdx + smallString.Length - 1;
    int leftSmallIdx = 0;
    int rightSmallIdx = smallString.Length - 1;
    while (leftBigidx <= rightBigIdx)
    {
        if (bigString[leftBigidx] != smallString[leftSmallIdx] ||
                bigString[rightBigIdx] != smallString[rightSmallIdx])
        {
            return false;
        }
        leftBigidx++;
        rightBigIdx--;
        leftSmallIdx++;
        rightSmallIdx--;
    }
    return true;
}

Test case

Test Case 1
{
  "bigString": "this is a big string",
  "smallStrings": ["this", "yo", "is", "a", "bigger", "string", "kappa"]
}

Test Case 2
{
  "bigString": "abcdefghijklmnopqrstuvwxyz",
  "smallStrings": ["abc", "mnopqr", "wyz", "no", "e", "tuuv"]
}

Test Case 3
{
  "bigString": "abcdefghijklmnopqrstuvwxyz",
  "smallStrings": ["abcdefghijklmnopqrstuvwxyz", "abc", "j", "mnopqr", "pqrstuvwxyz", "xyzz", "defh"]
}

Test Case 4
{
  "bigString": "hj!)!%Hj1jh8f1985n!)51",
  "smallStrings": ["%Hj7", "8f198", "!)5", "!)!", "!!", "jh81", "j181hf"]
}

Test Case 5
{
  "bigString": "Mary goes to the shopping center every week.",
  "smallStrings": ["to", "Mary", "centers", "shop", "shopping", "string", "kappa"]
}

Test Case 6
{
  "bigString": "adcb akfkw afnmc fkadn vkaca jdaf dacb cdba cbda",
  "smallStrings": ["abcd", "acbd", "adbc", "dabc", "cbda", "cabd", "cdab"]
}

Test Case 7
{
  "bigString": "test testing testings tests testers test-takers",
  "smallStrings": ["tests", "testatk", "testiing", "trsatii", "test-taker", "test"]
}

Test Case 8
{
  "bigString": "ndbajwhfawkjljkfaopwdlaawjk dawkj awjkawkfjhkawk ahjwkjad jadfljawd",
  "smallStrings": ["abc", "akwbc", "awbc", "abafac", "ajjfbc", "abac", "jadfl"]
}

Test Case 9
{
  "bigString": "Is this particular test going to pass or is it going to fail? That is the question.",
  "smallStrings": ["that", "the", "questions", "goes", "mountain", "passes", "passed", "going", "is"]
}

Test Case 10
{
  "bigString": "Everything in this test should fail.",
  "smallStrings": ["everything", "inn", "that", "testers", "shall", "failure"]
}

Test Case 11
{
  "bigString": "this ain't a big string",
  "smallStrings": ["this", "is", "yo", "a", "bigger"]
}

Test Case 12
{
  "bigString": "bbbabb",
  "smallStrings": ["bbabb"]
}