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:
class Solution { public int solution(int A, int B, int K); }
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 C#
Time spent on task 6 minutes
Notes
not defined yet
Code: 22:07:48 UTC,
java,
autosave
Code: 22:07:50 UTC,
cs,
autosave
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
}
}
Code: 22:07:59 UTC,
cs,
autosave
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = ((B-A))/K;
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Code: 22:08:20 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = ((B-A))/K;
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis
User test case 1:
[11, 345, 17]
Code: 22:10:52 UTC,
cs,
autosave
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value =
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Code: 22:11:10 UTC,
cs,
autosave
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Code: 22:11:22 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis
User test case 1:
[11, 345, 17]
Code: 22:11:40 UTC,
cs,
autosave
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Code: 22:11:43 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis
User test case 1:
[22, 45, 17]
Code: 22:12:27 UTC,
cs,
autosave
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Code: 22:12:34 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis
User test case 1:
[22, 51, 17]
Code: 22:12:50 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis
User test case 1:
[22, 47, 2]
Code: 22:12:56 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis
User test case 1:
[22, 47, 2]
Code: 22:12:58 UTC,
cs,
final,
score:
100
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
int value = (B/K)-(A/K);
if(A%K == 0)
{
value=value+1;
}
return value;
}
}
Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(1)
expand all
Correctness tests
1.
0.016 s
OK
1.
0.016 s
OK
2.
0.016 s
OK
1.
0.016 s
OK
2.
0.016 s
OK
3.
0.016 s
OK
1.
0.020 s
OK
2.
0.020 s
OK
3.
0.016 s
OK
4.
0.016 s
OK
5.
0.016 s
OK
6.
0.020 s
OK
expand all
Performance tests
1.
0.020 s
OK
1.
0.020 s
OK
1.
0.016 s
OK
2.
0.020 s
OK
1.
0.016 s
OK
2.
0.016 s
OK
3.
0.016 s
OK
4.
0.016 s
OK