longest common substring

Question

hi, please write a code for longest common sub string in two strings in c#? Input:s1="siva nagarjuna" s2="hello nagarjuna how r u" output:nagarjuna

Midhun Tp · Answer

Hi, Here is the code for that - public string LongestCommonSubstring(string str1, string str2) { string sequence = string.Empty; if (String.IsNullOrEmpty(str1) || String.IsNullOrEmpty(str2)) return ""; int[,] num = new int[str1.Length, str2.Length]; int maxlen = 0; int lastSubsBegin = 0; StringBuilder sequenceBuilder = new StringBuilder(); for (int i = 0; i { for (int j = 0; j { if (str1[i] != str2[j]) num[i, j] = 0; else { if ((i == 0) || (j == 0)) num[i, j] = 1; else num[i, j] = 1 + num[i - 1, j - 1]; if (num[i, j] > maxlen) { maxlen = num[i, j]; int thisSubsBegin = i - num[i, j] + 1; if (lastSubsBegin == thisSubsBegin) {//if the current LCS is the same as the last time this block ran sequenceBuilder.Append(str1[i]); } else //this block resets the string builder if a different LCS is found { lastSubsBegin = thisSubsBegin; sequenceBuilder.Length = 0; //clear it sequenceBuilder.Append(str1.Substring(lastSubsBegin, (i + 1) - lastSubsBegin)); } } } } } sequence = sequenceBuilder.ToString(); return sequence; } Pass your strings to above function. Yo will get the result. Reference : https://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Longest_common_substring

Manas Mohapatra · Answer

Try with below code: string s1 = "siva nagarjuna" ; string s2 = "hello nagarjuna how r siva u" ; string tempStr; List string > stringList = new List string >(); if (s1.Length > s2.Length) { tempStr = s1; s1 = s2; s2 = tempStr; } foreach ( string temp in s1.Split( ' ' )) { if (s2.Contains(temp)) { stringList.Add(temp); } } string bigList2 = (from s in stringList where s.Length == stringList.Max(a => a.Length) select s).FirstOrDefault();

siva nagarjuna · Answer

thanks for u r help Iwant know the code for in thi case also Input:s1="sivanagarjuna"; s2="hellonagarjunahowru" output:nagarjuna

Midhun Tp · Answer

Hi, Try below code - string s1 = "siva nagarjuna"; string s2 = "hello nagarjuna how r u"; string[] tempArr1 = s1.Split(' '); string[] tempArr2 = s2.Split(' '); int len = 0; string response = ""; for (int i = 0; i { if (tempArr1.Contains(tempArr2[i])) { if (tempArr2[i].Length > len) { response = tempArr2[i]; len = tempArr2[i].Length; } } } Response.Write(response); This will give the longest common words in two strings