O(n)
func
 
countkmers
(
sequence 
string
,
 k 
int
)
 
map
[
string
]
int
 
{
O(1)
  
var
 kmers 
=
 
make
(
map
[
string
]
int
)
----

O(1)
  
if
 k 
>
 
len
(
sequence
)
 
||
 k 
<=
 
0
 
{
O(1)
    
return
 kmers
----
  
}
----

O(1)
  
var
 tempSequence 
=
 sequence
[
:
k
]
O(1)
  kmers
[
tempSequence
]
++
----

O(n)
  
for
 i 
:=
 k
;
 i 
<
 
len
(
sequence
)
;
 i
++
 
{
O(1)
    tempSequence 
=
 tempSequence
[
1
:
]
 
+
 sequence
[
i
:
i
+
1
]
O(1)
    kmers
[
tempSequence
]
++
----
  
}
----

O(1)
  
return
 kmers
----
}