Tasks Details
medium
1.
CountDiv
Compute number of integers divisible by k in range [a..b].
Task Score
100%
Correctness
100%
Performance
100%
Write a function:
object Solution { def solution(a: Int, b: Int, k: Int): Int }
that, given three integers A, B and K, returns the number of integers within the range [A..B] that are divisible by K, i.e.:
{ i : A ≤ i ≤ B, i mod K = 0 }
For example, for A = 6, B = 11 and K = 2, your function should return 3, because there are three numbers divisible by 2 within the range [6..11], namely 6, 8 and 10.
Write an efficient algorithm for the following assumptions:
- A and B are integers within the range [0..2,000,000,000];
- K is an integer within the range [1..2,000,000,000];
- A ≤ B.
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Scala
Time spent on task 22 minutes
Notes
not defined yet
Code: 17:50:38 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
if (B == A) {
if (B % K == 0) 1
else 0
} else {
math.ceil((B - A).toDouble / K).toInt
}
}
}
Analysis
expand all
User tests
1.
1.760 s
OK
function result: 20
function result: 20
1.
1.768 s
OK
function result: 0
function result: 0
1.
1.742 s
OK
function result: 1
function result: 1
1.
1.737 s
OK
function result: 0
function result: 0
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
Code: 17:54:29 UTC,
scala,
verify,
result: Failed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
val base = (B - A) / K)
val extra =
if ((A % K == 0) || (B % K == 0)) 1
else 0
base + extra
}
}
Analysis
Compile error
Solution.scala:8: error: ';' expected but ')' found.
val base = (B - A) / K)
^
one error found
Code: 17:54:50 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
val base = (B - A) / K
val extra =
if ((A % K == 0) || (B % K == 0)) 1
else 0
base + extra
}
}
Analysis
expand all
User tests
1.
1.877 s
OK
function result: 19
function result: 19
1.
1.869 s
OK
function result: 0
function result: 0
1.
1.913 s
OK
function result: 1
function result: 1
1.
1.867 s
OK
function result: 0
function result: 0
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
Code: 17:55:30 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
val base = (B - A) / K
val extra =
if ((A % K == 0) || (B % K == 0)) 1
else 0
base + extra
}
}
Analysis
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
Code: 17:57:53 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
// val base = (B - A) / K
// val extra =
// if ((A % K == 0) || (B % K == 0)) 1
// else 0
// base + extra
math.ceil((B - A + 1).toDouble / K).toInt
}
}
Analysis
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
Code: 17:59:03 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
// val base = (B - A) / K
// val extra =
// if ((A % K == 0) || (B % K == 0)) 1
// else 0
// base + extra
math.ceil((B - A + 1).toDouble / K).toInt
}
}
Analysis
expand all
User tests
1.
1.831 s
OK
function result: 20
function result: 20
1.
1.808 s
OK
function result: 1
function result: 1
1.
1.808 s
OK
function result: 1
function result: 1
1.
1.798 s
OK
function result: 1
function result: 1
1.
1.801 s
OK
function result: 1
function result: 1
1.
1.911 s
OK
function result: 3
function result: 3
1.
1.904 s
OK
function result: 3
function result: 3
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
User test case 6:
[3, 7, 2]
User test case 7:
[4, 8, 2]
Code: 18:00:08 UTC,
scala,
verify,
result: Failed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
val base = (B - A + 1) / K
val extra =
if ((A % K == 0) || (B % K == 0)) 1
else 0
base + extra
// math.ceil((B - A + 1).toDouble / K).toInt
}
}
Analysis
expand all
Example tests
1.
1.563 s
WRONG ANSWER,
got 4 expected 3
expand all
User tests
1.
1.571 s
OK
function result: 19
function result: 19
1.
1.571 s
OK
function result: 0
function result: 0
1.
1.563 s
OK
function result: 1
function result: 1
1.
1.567 s
OK
function result: 0
function result: 0
1.
1.745 s
OK
function result: 1
function result: 1
1.
1.728 s
OK
function result: 2
function result: 2
1.
1.616 s
OK
function result: 3
function result: 3
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
User test case 6:
[3, 7, 2]
User test case 7:
[4, 8, 2]
Code: 18:05:13 UTC,
scala,
verify,
result: Failed
Analysis
expand all
Example tests
1.
2.216 s
WRONG ANSWER,
got 2 expected 3
expand all
User tests
1.
2.200 s
OK
function result: 19
function result: 19
1.
2.207 s
OK
function result: 0
function result: 0
1.
2.203 s
OK
function result: 0
function result: 0
1.
2.196 s
OK
function result: 0
function result: 0
1.
2.202 s
OK
function result: 0
function result: 0
1.
2.202 s
OK
function result: 1
function result: 1
1.
2.204 s
OK
function result: 2
function result: 2
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
User test case 6:
[3, 7, 2]
User test case 7:
[4, 8, 2]
Code: 18:05:42 UTC,
scala,
verify,
result: Failed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
// smallest number >= A that's divisble by K
val minDiv = math.ceil(A.toDouble / K).toInt * K
println(minDiv)
(B - minDiv) / K
}
}
Analysis
expand all
Example tests
1.
1.782 s
WRONG ANSWER,
got 2 expected 3
stdout:
6
expand all
User tests
1.
1.662 s
OK
function result: 19
function result: 19
stdout:
17
1.
1.663 s
OK
function result: 0
function result: 0
stdout:
14
1.
1.629 s
OK
function result: 0
function result: 0
stdout:
10
1.
1.599 s
OK
function result: 0
function result: 0
stdout:
20
1.
1.753 s
OK
function result: 0
function result: 0
stdout:
5
1.
1.663 s
OK
function result: 1
function result: 1
stdout:
4
1.
1.580 s
OK
function result: 2
function result: 2
stdout:
4
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
User test case 6:
[3, 7, 2]
User test case 7:
[4, 8, 2]
Code: 18:08:15 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
// smallest number >= A that's divisble by K
val minDiv = math.ceil(A.toDouble / K).toInt * K
if (minDiv > B) 0
else (B - minDiv) / K + 1
}
}
Analysis
expand all
User tests
1.
2.081 s
OK
function result: 20
function result: 20
1.
1.806 s
OK
function result: 0
function result: 0
1.
2.138 s
OK
function result: 1
function result: 1
1.
2.269 s
OK
function result: 0
function result: 0
1.
2.276 s
OK
function result: 1
function result: 1
1.
2.252 s
OK
function result: 2
function result: 2
1.
2.268 s
OK
function result: 3
function result: 3
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
User test case 6:
[3, 7, 2]
User test case 7:
[4, 8, 2]
Code: 18:09:25 UTC,
scala,
verify,
result: Passed
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
// smallest number >= A that's divisble by K
val minDiv = math.ceil(A.toDouble / K).toInt * K
if (minDiv > B) 0
else (B - minDiv) / K + 1
}
}
Analysis
expand all
User tests
1.
1.850 s
OK
function result: 20
function result: 20
1.
1.839 s
OK
function result: 0
function result: 0
1.
2.004 s
OK
function result: 1
function result: 1
1.
2.217 s
OK
function result: 0
function result: 0
1.
2.214 s
OK
function result: 1
function result: 1
1.
2.225 s
OK
function result: 2
function result: 2
1.
2.199 s
OK
function result: 3
function result: 3
User test case 1:
[11, 345, 17]
User test case 2:
[10, 10, 7]
User test case 3:
[10, 10, 5]
User test case 4:
[10, 10, 20]
User test case 5:
[4, 8, 5]
User test case 6:
[3, 7, 2]
User test case 7:
[4, 8, 2]
Code: 18:09:53 UTC,
scala,
final,
score:
100
import scala.collection.JavaConversions._
// you can use println for debugging purposes, e.g.
// println("this is a debug message")
object Solution {
def solution(A: Int, B: Int, K: Int): Int = {
// smallest number >= A that's divisble by K
val minDiv = math.ceil(A.toDouble / K).toInt * K
if (minDiv > B) 0
else (B - minDiv) / K + 1
}
}Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(1)
expand all
Correctness tests
1.
2.221 s
OK
1.
2.192 s
OK
2.
2.223 s
OK
1.
2.215 s
OK
2.
2.212 s
OK
3.
2.215 s
OK
1.
2.193 s
OK
2.
2.195 s
OK
3.
2.229 s
OK
4.
2.204 s
OK
5.
2.218 s
OK
6.
2.202 s
OK
expand all
Performance tests
1.
2.215 s
OK
1.
2.208 s
OK
1.
2.204 s
OK
2.
2.216 s
OK
1.
2.215 s
OK
2.
2.200 s
OK
3.
2.216 s
OK
4.
2.212 s
OK