Given a string, find the first repeating character in it.

Example

i/p - Vikrant
o/p - None
i/p - VikrantVikrant
o/p - Some(V)

Scala implementation:

object FirstUniqueChar extends App {
 def firstUnique(s: String): Option[Char] = {
 val countMap = (s groupBy (c=>c)) mapValues(_.length)
 def checkOccurence(s1: String ): Option[Char] = {
 if (countMap(s1.head) > 1) Some(s1.head)
 else if (s1.length == 1) None
 else checkOccurence(s1.tail)
 }
 checkOccurence(s)
 }
 println(firstUnique("abcdebC"))
 println(firstUnique("abcdef"))
}

I also have a followup question. What is the recommended way if I do not want to solve this problem with recursion? Instead of using the checkOccurence method I can traverse through the string and break when I find the first element with a count more than 1. But that will require a break, which is discouraged in Scala.

Given a string, find the first repeating character in it.

Examples:

• firstUnique("Vikrant") → None
• firstUnique("VikrantVikrant") → Some(V)

Scala implementation:

object FirstUniqueChar extends App {
 def firstUnique(s: String): Option[Char] = {
 val countMap = (s groupBy (c=>c)) mapValues(_.length)
 def checkOccurence(s1: String ): Option[Char] = {
 if (countMap(s1.head) > 1) Some(s1.head)
 else if (s1.length == 1) None
 else checkOccurence(s1.tail)
 }
 checkOccurence(s)
 }
 println(firstUnique("abcdebC"))
 println(firstUnique("abcdef"))
}

I also have a followup question. What is the recommended way if I do not want to solve this problem with recursion? Instead of using the checkOccurence method I can traverse through the string and break when I find the first element with a count more than 1. But that will require a break, which is discouraged in Scala.

Given a string, find the first non-repeating character in it.

Example

i/p - Vikrant
o/p - None
i/p - VikrantVikrant
o/p - Some(V)

Scala implementation:

object FirstUniqueChar extends App {
 def firstUnique(s: String): Option[Char] = {
 val countMap = (s groupBy (c=>c)) mapValues(_.length)
 def checkOccurence(s1: String ): Option[Char] = {
 if (countMap(s1.head) > 1) Some(s1.head)
 else if (s1.length == 1) None
 else checkOccurence(s1.tail)
 }
 checkOccurence(s)
 }
 println(firstUnique("abcdebC"))
 println(firstUnique("abcdef"))
}

I also have a followup question. What is the recommended way if I do not want to solve this problem with recursion? Instead of using the checkOccurence method I can traverse through the string and break when I find the first element with a count more than 1. But that will require a break, which is discouraged in Scala.

Given a string, find the first repeating character in it.

Example

i/p - Vikrant
o/p - None
i/p - VikrantVikrant
o/p - Some(V)

Scala implementation:

object FirstUniqueChar extends App {
 def firstUnique(s: String): Option[Char] = {
 val countMap = (s groupBy (c=>c)) mapValues(_.length)
 def checkOccurence(s1: String ): Option[Char] = {
 if (countMap(s1.head) > 1) Some(s1.head)
 else if (s1.length == 1) None
 else checkOccurence(s1.tail)
 }
 checkOccurence(s)
 }
 println(firstUnique("abcdebC"))
 println(firstUnique("abcdef"))
}

I also have a followup question. What is the recommended way if I do not want to solve this problem with recursion? Instead of using the checkOccurence method I can traverse through the string and break when I find the first element with a count more than 1. But that will require a break, which is discouraged in Scala.

Given a string, find the first non-repeating character in it.

example

i/p - Vikrant
o/p - None
i/p - VikrantVikrant
o/p - Some(V)

Here is scala implementation

object FirstUniqueChar extends App {
 def firstUnique(s: String): Option[Char] = {
 val countMap = (s groupBy (c=>c)) mapValues(_.length)
 def checkOccurence(s1: String ): Option[Char] = {
 if (countMap(s1.head) > 1) Some(s1.head)
 else if (s1.length == 1) None
 else checkOccurence(s1.tail)
 }
 checkOccurence(s)
 }
 println(firstUnique("abcdebC"))
 println(firstUnique("abcdef"))
}

I also have a followup question. What is the recommended way if I do not want to solve this problem with recursion. Instead of using checkOccurence method I can traverse through the string an break when I find first element with count more than 1. But that will require a break, which is discouraged in Scala.

Given a string, find the first non-repeating character in it.

Example

i/p - Vikrant
o/p - None
i/p - VikrantVikrant
o/p - Some(V)

Scala implementation:

object FirstUniqueChar extends App {
 def firstUnique(s: String): Option[Char] = {
 val countMap = (s groupBy (c=>c)) mapValues(_.length)
 def checkOccurence(s1: String ): Option[Char] = {
 if (countMap(s1.head) > 1) Some(s1.head)
 else if (s1.length == 1) None
 else checkOccurence(s1.tail)
 }
 checkOccurence(s)
 }
 println(firstUnique("abcdebC"))
 println(firstUnique("abcdef"))
}

I also have a followup question. What is the recommended way if I do not want to solve this problem with recursion? Instead of using the checkOccurence method I can traverse through the string and break when I find the first element with a count more than 1. But that will require a break, which is discouraged in Scala.