Skip to main content

Find longest substring of unique characters

Here given code implementation process.

//C Program
//Find longest substring of unique characters
#include <stdio.h>

//find the longest unique substring of a string
void longest_unique_substring(char * text, int size)
{
	if (size <= 1)
	{
		return;
	}
	int length = -1, x = 0, front = 0;
	//Loop controlling variable
	int i = 1, j = 0;
	//Loop iterating the string elements
	for (i = 1; i < size; ++i)
	{
		// check that whether [i] location character exists 
		// with between of [x to i] location or not
		for (j = x; j < i; j++)
		{
			if (text[j] == text[i])
			{
				//When character exists 
				break;
			}
		}
		if (j == i)
		{
			//When get a new substring
			if ((j - x) > length)
			{
				// When get a newly longest unique substring
				// Get length
				length = j - x;
				// Get starting location
				front = x;
			}
		}
		else
		{
			x = x + 1;
			i = x;
		}
	}
	printf(" Given String : %s\n", text);
	printf(" Longest Unique Substring : ");
	//Note that at least one unique character always exist in string
	for (i = front; i <= front + length; ++i)
	{
		printf("%c", text[i]);
	}
	printf("\n");
}
int main()
{
	//Define the character of array elements
	char text[] = "ABCABD";
	//Get the size
	int size = sizeof(text) / sizeof(text[0]) - 1;
	//Find result
	longest_unique_substring(text, size);
	//Other test cases
	char text1[] = "FBCSBSNL";
	size = sizeof(text1) / sizeof(text1[0]) - 1;
	longest_unique_substring(text1, size);
	char text2[] = "AABFBCAEBO";
	size = sizeof(text2) / sizeof(text2[0]) - 1;
	longest_unique_substring(text2, size);
	char text3[] = "AABAAAB";
	size = sizeof(text3) / sizeof(text3[0]) - 1;
	longest_unique_substring(text3, size);
	char text4[] = "BAACCAAB";
	size = sizeof(text4) / sizeof(text4[0]) - 1;
	longest_unique_substring(text4, size);
	return 0;
}

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
//Java Program 
//Find longest substring of unique characters
class MyString
{
	//Find the longest unique substring of a string
	public void longest_unique_substring(String text)
	{
		int size = text.length();
		if (size <= 1)
		{
			return;
		}
		int length = -1, x = 0, front = 0;
		//Loop controlling variable
		int i = 1, j = 0;
		//Loop iterating the string elements
		for (i = 1; i < size; ++i)
		{
			// check that whether [i] location character exists 
			// with between of [x to i] location or not
			for (j = x; j < i; j++)
			{
				if (text.charAt(j) == text.charAt(i))
				{
					break;
				}
			}
			if (j == i)
			{
				//When get a new substring
				if ((j - x) > length)
				{
					// When get a newly longest unique substring
					// Get length
					length = j - x;
					// Get starting location
					front = x;
				}
			}
			else
			{
				x = x + 1;
				i = x;
			}
		}
		System.out.print(" Given String : " + text + "\n");
		System.out.print(" Longest Unique Substring : ");
		//Note that at least one unique character always exist in string
		for (i = front; i <= front + length; ++i)
		{
			System.out.print(text.charAt(i));
		}
		System.out.print("\n");
	}
	public static void main(String[] args)
	{
		MyString obj = new MyString();
		obj.longest_unique_substring("ABCABD");
		obj.longest_unique_substring("FBCSBSNL");
		obj.longest_unique_substring("AABFBCAEBO");
		obj.longest_unique_substring("AABAAAB");
		obj.longest_unique_substring("BAACCAAB");
	}
}

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
//Include header file
#include <iostream>
#include<string.h>

using namespace std;
//C++ Program 
//Find longest substring of unique characters
class MyString
{
	public:
		//Find the longest unique substring of a string
		void longest_unique_substring(string text)
		{
			int size = text.size();
			if (size <= 1)
			{
				return;
			}
			int length = -1, x = 0, front = 0;
			//Loop controlling variable
			int i = 1, j = 0;
			//Loop iterating the string elements
			for (i = 1; i < size; ++i)
			{
				// check that whether [i] location character exists 
				// with between of [x to i] location or not
				for (j = x; j < i; j++)
				{
					if (text[j] == text[i])
					{
						break;
					}
				}
				if (j == i)
				{
					//When get a new substring
					if ((j - x) > length)
					{
						// When get a newly longest unique substring
						// Get length
						length = j - x;
						// Get starting location
						front = x;
					}
				}
				else
				{
					x = x + 1;
					i = x;
				}
			}
			cout << " Given String : " << text << "\n";
			cout << " Longest Unique Substring : ";
			//Note that at least one unique character always exist in string
			for (i = front; i <= front + length; ++i)
			{
				cout << text[i];
			}
			cout << "\n";
		}
};
int main()
{
	MyString obj = MyString();
	obj.longest_unique_substring("ABCABD");
	obj.longest_unique_substring("FBCSBSNL");
	obj.longest_unique_substring("AABFBCAEBO");
	obj.longest_unique_substring("AABAAAB");
	obj.longest_unique_substring("BAACCAAB");
	return 0;
}

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
//Include namespace system
using System;
//C# Program 
//Find longest substring of unique characters
class MyString
{
	//Find the longest unique substring of a string
	public void longest_unique_substring(String text)
	{
		int size = text.Length;
		if (size <= 1)
		{
			return;
		}
		int length = -1, x = 0, front = 0;
		//Loop controlling variable
		int i = 1, j = 0;
		//Loop iterating the string elements
		for (i = 1; i < size; ++i)
		{
			// check that whether [i] location character exists 
			// with between of [x to i] location or not
			for (j = x; j < i; j++)
			{
				if (text[j] == text[i])
				{
					break;
				}
			}
			if (j == i)
			{
				//When get a new substring
				if ((j - x) > length)
				{
					// When get a newly longest unique substring
					// Get length
					length = j - x;
					// Get starting location
					front = x;
				}
			}
			else
			{
				x = x + 1;
				i = x;
			}
		}
		Console.Write(" Given String : " + text + "\n");
		Console.Write(" Longest Unique Substring : ");
		//Note that at least one unique character always exist in string
		for (i = front; i <= front + length; ++i)
		{
			Console.Write(text[i]);
		}
		Console.Write("\n");
	}
	public static void Main(String[] args)
	{
		MyString obj = new MyString();
		obj.longest_unique_substring("ABCABD");
		obj.longest_unique_substring("FBCSBSNL");
		obj.longest_unique_substring("AABFBCAEBO");
		obj.longest_unique_substring("AABAAAB");
		obj.longest_unique_substring("BAACCAAB");
	}
}

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
<?php
//Php Program 
//Find longest substring of unique characters
class MyString
{
	//Find the longest unique substring of a string
	public	function longest_unique_substring($text)
	{
		$size = strlen($text);
		if ($size <= 1)
		{
			return;
		}
		$length = -1;
		$x = 0;
		$front = 0;
		//Loop controlling variable
		$i = 1;
		$j = 0;
		//Loop iterating the string elements
		for ($i = 1; $i < $size; ++$i)
		{
			// check that whether [i] location character exists 
			// with between of [x to i] location or not
			for ($j = $x; $j < $i; $j++)
			{
				if ($text[$j] == $text[$i])
				{
					break;
				}
			}
			if ($j == $i)
			{
				//When get a new substring
				if (($j - $x) > $length)
				{
					// When get a newly longest unique substring
					// Get length
					$length = $j - $x;
					// Get starting location
					$front = $x;
				}
			}
			else
			{
				$x = $x + 1;
				$i = $x;
			}
		}
		echo " Given String : ". $text ."\n";
		echo " Longest Unique Substring : ";
		//Note that at least one unique character always exist in string
		for ($i = $front; $i <= $front + $length; ++$i)
		{
			echo $text[$i];
		}
		echo "\n";
	}
}

function main()
{
	$obj = new MyString();
	$obj->longest_unique_substring("ABCABD");
	$obj->longest_unique_substring("FBCSBSNL");
	$obj->longest_unique_substring("AABFBCAEBO");
	$obj->longest_unique_substring("AABAAAB");
	$obj->longest_unique_substring("BAACCAAB");
}
main();

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
//Node Js Program 
//Find longest substring of unique characters
class MyString
{
	//Find the longest unique substring of a string
	longest_unique_substring(text)
	{
		var size = text.length;
		if (size <= 1)
		{
			return;
		}
		var length = -1;
		var x = 0;
		var front = 0;
		//Loop controlling variable
		var i = 1;
		var j = 0;
		//Loop iterating the string elements
		for (i = 1; i < size; ++i)
		{
			// check that whether [i] location character exists 
			// with between of [x to i] location or not
			for (j = x; j < i; j++)
			{
				if (text[j] == text[i])
				{
					break;
				}
			}
			if (j == i)
			{
				//When get a new substring
				if ((j - x) > length)
				{
					// When get a newly longest unique substring
					// Get length
					length = j - x;
					// Get starting location
					front = x;
				}
			}
			else
			{
				x = x + 1;
				i = x;
			}
		}
		process.stdout.write(" Given String : " + text + "\n");
		process.stdout.write(" Longest Unique Substring : ");
		//Note that at least one unique character always exist in string
		for (i = front; i <= front + length; ++i)
		{
			process.stdout.write(text[i]);
		}
		process.stdout.write("\n");
	}
}

function main()
{
	var obj = new MyString();
	obj.longest_unique_substring("ABCABD");
	obj.longest_unique_substring("FBCSBSNL");
	obj.longest_unique_substring("AABFBCAEBO");
	obj.longest_unique_substring("AABAAAB");
	obj.longest_unique_substring("BAACCAAB");
}
main();

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
# Python 3 Program 
# Find longest substring of unique characters
class MyString :
	# Find the longest unique substring of a string
	def longest_unique_substring(self, text) :
		size = len(text)
		if (size <= 1) :
			return
		
		length = -1
		x = 0
		front = 0
		# Loop controlling variable
		i = 1
		j = 0
		# Loop iterating the string elements
		while (i < size) :
			#  check that whether [i] location character exists 
			#  with between of [x to i] location or not
			j = x
			while (j < i) :
				if (text[j] == text[i]) :
					break
				
				j += 1
			
			if (j == i) :
				# When get a new substring
				if ((j - x) > length) :
					#  When get a newly longest unique substring
					#  Get length
					length = j - x
					#  Get starting location
					front = x
				
			else :
				x = x + 1
				i = x
			
			i += 1
		
		print(" Given String : ", text ,"\n", end = "")
		print(" Longest Unique Substring : ", end = "")
		# Note that at least one unique character always exist in string
		i = front
		while (i <= front + length) :
			print(text[i], end = "")
			i += 1
		
		print("\n", end = "")
	

def main() :
	obj = MyString()
	obj.longest_unique_substring("ABCABD")
	obj.longest_unique_substring("FBCSBSNL")
	obj.longest_unique_substring("AABFBCAEBO")
	obj.longest_unique_substring("AABAAAB")
	obj.longest_unique_substring("BAACCAAB")

if __name__ == "__main__": main()

Output

 Given String :  ABCABD
 Longest Unique Substring : CABD
 Given String :  FBCSBSNL
 Longest Unique Substring : FBCS
 Given String :  AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String :  AABAAAB
 Longest Unique Substring : AB
 Given String :  BAACCAAB
 Longest Unique Substring : BA
# Ruby Program 
# Find longest substring of unique characters
class MyString

	# Find the longest unique substring of a string
	def longest_unique_substring(text)
	
		size = text.length()
		if (size <= 1)
		
			return
		end
		length = -1
		x = 0
		front = 0
		# Loop controlling variable
		i = 1
		j = 0
		# Loop iterating the string elements
		while (i < size)
		
			#  check that whether [i] location character exists 
			#  with between of [x to i] location or not
			j = x
			while (j < i)
			
				if (text[j] == text[i])
				
					break
				end
				j += 1
			end
			if (j == i)
			
				# When get a new substring
				if ((j - x) > length)
				
					#  When get a newly longest unique substring
					#  Get length
					length = j - x
					#  Get starting location
					front = x
				end
			else
			
				x = x + 1
				i = x
			end
			i += 1
		end
		print(" Given String : ", text ,"\n")
		print(" Longest Unique Substring : ")
		# Note that at least one unique character always exist in string
		i = front
		while (i <= front + length)
		
			print(text[i])
			i += 1
		end
		print("\n")
	end
end
def main()

	obj = MyString.new()
	obj.longest_unique_substring("ABCABD")
	obj.longest_unique_substring("FBCSBSNL")
	obj.longest_unique_substring("AABFBCAEBO")
	obj.longest_unique_substring("AABAAAB")
	obj.longest_unique_substring("BAACCAAB")
end
main()

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA

import scala.util.control.Breaks._
//Scala Program 
//Find longest substring of unique characters
class MyString
{
	//Find the longest unique substring of a string
	def longest_unique_substring(text: String): Unit = {
		var size: Int = text.length();
		if (size <= 1)
		{
			return;
		}
		var length: Int = -1;
		var x: Int = 0;
		var front: Int = 0;
		//Loop controlling variable
		var i: Int = 1;
		var j: Int = 0;
		//Loop iterating the string elements
		while (i < size)
		{
			// check that whether [i] location character exists 
			// with between of [x to i] location or not
			j = x;
          	breakable {
			while (j < i)
			{
				if (text(j) == text(i))
				{
					break;
				}
				j += 1;
			}
            }
			if (j == i)
			{
				//When get a new substring
				if ((j - x) > length)
				{
					// When get a newly longest unique substring
					// Get length
					length = j - x;
					// Get starting location
					front = x;
				}
			}
			else
			{
				x = x + 1;
				i = x;
			}
			i += 1;
		}
		print(" Given String : " + text + "\n");
		print(" Longest Unique Substring : ");
		//Note that at least one unique character always exist in string
		i = front;
		while (i <= front + length)
		{
			print(text(i));
			i += 1;
		}
		print("\n");
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var obj: MyString = new MyString();
		obj.longest_unique_substring("ABCABD");
		obj.longest_unique_substring("FBCSBSNL");
		obj.longest_unique_substring("AABFBCAEBO");
		obj.longest_unique_substring("AABAAAB");
		obj.longest_unique_substring("BAACCAAB");
	}
}

Output

 Given String : ABCABD
 Longest Unique Substring : CABD
 Given String : FBCSBSNL
 Longest Unique Substring : FBCS
 Given String : AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String : AABAAAB
 Longest Unique Substring : AB
 Given String : BAACCAAB
 Longest Unique Substring : BA
//Swift Program 
//Find longest substring of unique characters
class MyString
{
	//Find the longest unique substring of a string
	func longest_unique_substring(_ str: String)
	{
		let size: Int = str.count;
      
		if (size <= 1)
		{
			return;
		}
      	let text = Array(str);
		var length: Int = -1;
		var x: Int = 0;
		var front: Int = 0;
		//Loop controlling variable
		var i: Int = 1;
		var j: Int = 0;
		//Loop iterating the string elements
		while (i < size)
		{
			// check that whether [i] location character exists 
			// with between of [x to i] location or not
			j = x;
			while (j < i)
			{
				if (text[j] == text[i])
				{
					break;
				}
				j += 1;
			}
			if (j == i)
			{
				//When get a new substring
				if ((j - x) > length)
				{
					// When get a newly longest unique substring
					// Get length
					length = j - x;
					// Get starting location
					front = x;
				}
			}
			else
			{
				x = x + 1;
				i = x;
			}
			i += 1;
		}
		print(" Given String : ", str ,"\n", terminator: "");
		print(" Longest Unique Substring : ", terminator: "");
		//Note that at least one unique character always exist in string
		i = front;
		while (i <= front + length)
		{
			print(text[i], terminator: "");
			i += 1;
		}
		print("\n", terminator: "");
	}
}
func main()
{
	let obj: MyString = MyString();
	obj.longest_unique_substring("ABCABD");
	obj.longest_unique_substring("FBCSBSNL");
	obj.longest_unique_substring("AABFBCAEBO");
	obj.longest_unique_substring("AABAAAB");
	obj.longest_unique_substring("BAACCAAB");
}
main();

Output

 Given String :  ABCABD
 Longest Unique Substring : CABD
 Given String :  FBCSBSNL
 Longest Unique Substring : FBCS
 Given String :  AABFBCAEBO
 Longest Unique Substring : FBCAE
 Given String :  AABAAAB
 Longest Unique Substring : AB
 Given String :  BAACCAAB
 Longest Unique Substring : BA
Last updated on by Kalkicode




Comment

Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.

New Comment