set increment using flatMap
I have a mutuable set and assigning the values to it from input
var set = scala.collection.mutable.Set[Int]()
set ++= (in.readLine().split(" ").map(_.toInt))
Input:
1 5
Actual Output:
1,5
Required Output:
1,2,3,4,5
If have used flatMap with condition, but got error. How to achieve this with flatMap
scala
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
|
show 1 more comment
I have a mutuable set and assigning the values to it from input
var set = scala.collection.mutable.Set[Int]()
set ++= (in.readLine().split(" ").map(_.toInt))
Input:
1 5
Actual Output:
1,5
Required Output:
1,2,3,4,5
If have used flatMap with condition, but got error. How to achieve this with flatMap
scala
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
2
If have used flatMap with condition, but got error.Can you post what you tried and the error exactly ?
– Chirlo
Nov 22 '18 at 9:18
2
If the input is only 2 values why should the output have 5 values? ASetonly contains what you put in it (minus any duplicates).
– jwvh
Nov 22 '18 at 9:22
1
why you are so obsessed with flatMap why do you want to use only flat map? as i can see you are giving 2 int in the input which are space separated and if you will split it it's going to give you List("1", "5") now what makes you think you can use flatMap on that?
– Raman Mishra
Nov 22 '18 at 9:26
3
It seems, that you simply misunderstoodflatMapand now you have wrong expectations.
– ygor
Nov 22 '18 at 9:28
1
I perhaps you meanRangeinstead ofSet.
– ygor
Nov 22 '18 at 9:30
|
show 1 more comment
I have a mutuable set and assigning the values to it from input
var set = scala.collection.mutable.Set[Int]()
set ++= (in.readLine().split(" ").map(_.toInt))
Input:
1 5
Actual Output:
1,5
Required Output:
1,2,3,4,5
If have used flatMap with condition, but got error. How to achieve this with flatMap
scala
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
I have a mutuable set and assigning the values to it from input
var set = scala.collection.mutable.Set[Int]()
set ++= (in.readLine().split(" ").map(_.toInt))
Input:
1 5
Actual Output:
1,5
Required Output:
1,2,3,4,5
If have used flatMap with condition, but got error. How to achieve this with flatMap
scala
scala
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
asked Nov 22 '18 at 9:17
Sivakumar MSivakumar M
175
175
2
If have used flatMap with condition, but got error.Can you post what you tried and the error exactly ?
– Chirlo
Nov 22 '18 at 9:18
2
If the input is only 2 values why should the output have 5 values? ASetonly contains what you put in it (minus any duplicates).
– jwvh
Nov 22 '18 at 9:22
1
why you are so obsessed with flatMap why do you want to use only flat map? as i can see you are giving 2 int in the input which are space separated and if you will split it it's going to give you List("1", "5") now what makes you think you can use flatMap on that?
– Raman Mishra
Nov 22 '18 at 9:26
3
It seems, that you simply misunderstoodflatMapand now you have wrong expectations.
– ygor
Nov 22 '18 at 9:28
1
I perhaps you meanRangeinstead ofSet.
– ygor
Nov 22 '18 at 9:30
|
show 1 more comment
2
If have used flatMap with condition, but got error.Can you post what you tried and the error exactly ?
– Chirlo
Nov 22 '18 at 9:18
2
If the input is only 2 values why should the output have 5 values? ASetonly contains what you put in it (minus any duplicates).
– jwvh
Nov 22 '18 at 9:22
1
why you are so obsessed with flatMap why do you want to use only flat map? as i can see you are giving 2 int in the input which are space separated and if you will split it it's going to give you List("1", "5") now what makes you think you can use flatMap on that?
– Raman Mishra
Nov 22 '18 at 9:26
3
It seems, that you simply misunderstoodflatMapand now you have wrong expectations.
– ygor
Nov 22 '18 at 9:28
1
I perhaps you meanRangeinstead ofSet.
– ygor
Nov 22 '18 at 9:30
2
2
If have used flatMap with condition, but got error. Can you post what you tried and the error exactly ?– Chirlo
Nov 22 '18 at 9:18
If have used flatMap with condition, but got error. Can you post what you tried and the error exactly ?– Chirlo
Nov 22 '18 at 9:18
2
2
If the input is only 2 values why should the output have 5 values? A
Set only contains what you put in it (minus any duplicates).– jwvh
Nov 22 '18 at 9:22
If the input is only 2 values why should the output have 5 values? A
Set only contains what you put in it (minus any duplicates).– jwvh
Nov 22 '18 at 9:22
1
1
why you are so obsessed with flatMap why do you want to use only flat map? as i can see you are giving 2 int in the input which are space separated and if you will split it it's going to give you List("1", "5") now what makes you think you can use flatMap on that?
– Raman Mishra
Nov 22 '18 at 9:26
why you are so obsessed with flatMap why do you want to use only flat map? as i can see you are giving 2 int in the input which are space separated and if you will split it it's going to give you List("1", "5") now what makes you think you can use flatMap on that?
– Raman Mishra
Nov 22 '18 at 9:26
3
3
It seems, that you simply misunderstood
flatMap and now you have wrong expectations.– ygor
Nov 22 '18 at 9:28
It seems, that you simply misunderstood
flatMap and now you have wrong expectations.– ygor
Nov 22 '18 at 9:28
1
1
I perhaps you mean
Range instead of Set.– ygor
Nov 22 '18 at 9:30
I perhaps you mean
Range instead of Set.– ygor
Nov 22 '18 at 9:30
|
show 1 more comment
2 Answers
2
active
oldest
votes
I assume you have always a String like '2 5' as Input:
The solution could look like:
def toSeq(value: String): Seq[Int] = {
value.split(" ")
.map(_.toInt).toList match {
case x1::x2::_ => x1 to x2
case other => Nil// handle Exception
}
}
println(toSeq("1 5").toList)
Be aware that the input is not validated!
answered Nov 22 '18 at 9:45
pmepme
2,55711325
add a comment |
My opinion is, there is no need for flatMap operation here. You might have received compiler error saying invalid syntax. yet i'm going ahead and give you the solution if I really understand your question.
val in = "1 5"
var set = scala.collection.mutable.Set[Int]()
set.++=(in.split(" ").flatMap(value => Set(value.trim.toInt)))
val range = set.head to set.last
println( range.mkString(","))
Result
1,2,3,4,5
You might have noticed that only change I had done is , return the value in Set(_).
The nature of the flatMap operation is, it flats multiple collections into single collection hence I'm returning it as Set(_)
An easiest alternative I would think of is
val in = "1 5"
val split = in.split(" ")
val range = split(0).trim.toInt to split(1).trim.toInt
println(range.mkString(","))
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
1
Usingset.headandset.lastis basically never right (unless you have aSortedSet, or aLinkedHashSet, or some other subtype which guarantees iteration order).
– Alexey Romanov
Nov 22 '18 at 10:07
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
I assume you have always a String like '2 5' as Input:
The solution could look like:
def toSeq(value: String): Seq[Int] = {
value.split(" ")
.map(_.toInt).toList match {
case x1::x2::_ => x1 to x2
case other => Nil// handle Exception
}
}
println(toSeq("1 5").toList)
Be aware that the input is not validated!
answered Nov 22 '18 at 9:45
pmepme
2,55711325
add a comment |
I assume you have always a String like '2 5' as Input:
The solution could look like:
def toSeq(value: String): Seq[Int] = {
value.split(" ")
.map(_.toInt).toList match {
case x1::x2::_ => x1 to x2
case other => Nil// handle Exception
}
}
println(toSeq("1 5").toList)
Be aware that the input is not validated!
answered Nov 22 '18 at 9:45
pmepme
2,55711325
add a comment |
I assume you have always a String like '2 5' as Input:
The solution could look like:
def toSeq(value: String): Seq[Int] = {
value.split(" ")
.map(_.toInt).toList match {
case x1::x2::_ => x1 to x2
case other => Nil// handle Exception
}
}
println(toSeq("1 5").toList)
Be aware that the input is not validated!
answered Nov 22 '18 at 9:45
pmepme
2,55711325
I assume you have always a String like '2 5' as Input:
The solution could look like:
def toSeq(value: String): Seq[Int] = {
value.split(" ")
.map(_.toInt).toList match {
case x1::x2::_ => x1 to x2
case other => Nil// handle Exception
}
}
println(toSeq("1 5").toList)
Be aware that the input is not validated!
answered Nov 22 '18 at 9:45
pmepme
2,55711325
edited Nov 22 '18 at 10:08
answered Nov 22 '18 at 9:45
pmepme
2,55711325
answered Nov 22 '18 at 9:45
pmepme
2,55711325
answered Nov 22 '18 at 9:45
pmepme
2,55711325
2,55711325
add a comment |
add a comment |
My opinion is, there is no need for flatMap operation here. You might have received compiler error saying invalid syntax. yet i'm going ahead and give you the solution if I really understand your question.
val in = "1 5"
var set = scala.collection.mutable.Set[Int]()
set.++=(in.split(" ").flatMap(value => Set(value.trim.toInt)))
val range = set.head to set.last
println( range.mkString(","))
Result
1,2,3,4,5
You might have noticed that only change I had done is , return the value in Set(_).
The nature of the flatMap operation is, it flats multiple collections into single collection hence I'm returning it as Set(_)
An easiest alternative I would think of is
val in = "1 5"
val split = in.split(" ")
val range = split(0).trim.toInt to split(1).trim.toInt
println(range.mkString(","))
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
1
Usingset.headandset.lastis basically never right (unless you have aSortedSet, or aLinkedHashSet, or some other subtype which guarantees iteration order).
– Alexey Romanov
Nov 22 '18 at 10:07
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
add a comment |
My opinion is, there is no need for flatMap operation here. You might have received compiler error saying invalid syntax. yet i'm going ahead and give you the solution if I really understand your question.
val in = "1 5"
var set = scala.collection.mutable.Set[Int]()
set.++=(in.split(" ").flatMap(value => Set(value.trim.toInt)))
val range = set.head to set.last
println( range.mkString(","))
Result
1,2,3,4,5
You might have noticed that only change I had done is , return the value in Set(_).
The nature of the flatMap operation is, it flats multiple collections into single collection hence I'm returning it as Set(_)
An easiest alternative I would think of is
val in = "1 5"
val split = in.split(" ")
val range = split(0).trim.toInt to split(1).trim.toInt
println(range.mkString(","))
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
1
Usingset.headandset.lastis basically never right (unless you have aSortedSet, or aLinkedHashSet, or some other subtype which guarantees iteration order).
– Alexey Romanov
Nov 22 '18 at 10:07
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
add a comment |
My opinion is, there is no need for flatMap operation here. You might have received compiler error saying invalid syntax. yet i'm going ahead and give you the solution if I really understand your question.
val in = "1 5"
var set = scala.collection.mutable.Set[Int]()
set.++=(in.split(" ").flatMap(value => Set(value.trim.toInt)))
val range = set.head to set.last
println( range.mkString(","))
Result
1,2,3,4,5
You might have noticed that only change I had done is , return the value in Set(_).
The nature of the flatMap operation is, it flats multiple collections into single collection hence I'm returning it as Set(_)
An easiest alternative I would think of is
val in = "1 5"
val split = in.split(" ")
val range = split(0).trim.toInt to split(1).trim.toInt
println(range.mkString(","))
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
My opinion is, there is no need for flatMap operation here. You might have received compiler error saying invalid syntax. yet i'm going ahead and give you the solution if I really understand your question.
val in = "1 5"
var set = scala.collection.mutable.Set[Int]()
set.++=(in.split(" ").flatMap(value => Set(value.trim.toInt)))
val range = set.head to set.last
println( range.mkString(","))
Result
1,2,3,4,5
You might have noticed that only change I had done is , return the value in Set(_).
The nature of the flatMap operation is, it flats multiple collections into single collection hence I'm returning it as Set(_)
An easiest alternative I would think of is
val in = "1 5"
val split = in.split(" ")
val range = split(0).trim.toInt to split(1).trim.toInt
println(range.mkString(","))
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
edited Nov 22 '18 at 9:44
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
answered Nov 22 '18 at 9:28
Balaji ReddyBalaji Reddy
2,98331634
2,98331634
1
Usingset.headandset.lastis basically never right (unless you have aSortedSet, or aLinkedHashSet, or some other subtype which guarantees iteration order).
– Alexey Romanov
Nov 22 '18 at 10:07
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
add a comment |
1
Usingset.headandset.lastis basically never right (unless you have aSortedSet, or aLinkedHashSet, or some other subtype which guarantees iteration order).
– Alexey Romanov
Nov 22 '18 at 10:07
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
1
1
Using
set.head and set.last is basically never right (unless you have a SortedSet, or a LinkedHashSet, or some other subtype which guarantees iteration order).– Alexey Romanov
Nov 22 '18 at 10:07
Using
set.head and set.last is basically never right (unless you have a SortedSet, or a LinkedHashSet, or some other subtype which guarantees iteration order).– Alexey Romanov
Nov 22 '18 at 10:07
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
@AlexeyRomanov I agree
– Balaji Reddy
Nov 22 '18 at 10:14
add a comment |
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2
If have used flatMap with condition, but got error.Can you post what you tried and the error exactly ?– Chirlo
Nov 22 '18 at 9:18
2
If the input is only 2 values why should the output have 5 values? A
Setonly contains what you put in it (minus any duplicates).– jwvh
Nov 22 '18 at 9:22
1
why you are so obsessed with flatMap why do you want to use only flat map? as i can see you are giving 2 int in the input which are space separated and if you will split it it's going to give you List("1", "5") now what makes you think you can use flatMap on that?
– Raman Mishra
Nov 22 '18 at 9:26
3
It seems, that you simply misunderstood
flatMapand now you have wrong expectations.– ygor
Nov 22 '18 at 9:28
1
I perhaps you mean
Rangeinstead ofSet.– ygor
Nov 22 '18 at 9:30