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 Java 21
Time spent on task 21 minutes
Notes
not defined yet
Code: 06:12:17 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
count=count+(b/a)*(a/k);
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
User test case 1:
[10, 14, 2]
Code: 06:19:51 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
count=count+(b/a)*(a/k);
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
Code: 06:20:14 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
count=count+(b/a)*(a/k);
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.321 s
OK
function result: 5
function result: 5
1.
1.312 s
OK
function result: 1
function result: 1
1.
1.307 s
OK
function result: 11
function result: 11
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:21:23 UTC,
java,
verify,
result: Failed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(k<a){
a=k;
}
if(a!=b){
count=count+(b/a)*(a/k);
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
Example tests
1.
1.309 s
WRONG ANSWER,
got 5 expected 3
expand all
User tests
1.
1.325 s
OK
function result: 7
function result: 7
1.
1.327 s
OK
function result: 1
function result: 1
1.
1.311 s
OK
function result: 19
function result: 19
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:22:09 UTC,
java,
verify,
result: Failed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(k<a){
count=b-a;
}
if(a!=b){
count=count+(b/a)*(a/k);
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
Example tests
1.
1.258 s
WRONG ANSWER,
got 7 expected 3
expand all
User tests
1.
1.187 s
OK
function result: 9
function result: 9
1.
1.328 s
OK
function result: 1
function result: 1
1.
1.330 s
OK
function result: 19
function result: 19
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:22:29 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
count=count+(b/a)*(a/k);
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.334 s
OK
function result: 5
function result: 5
1.
1.323 s
OK
function result: 1
function result: 1
1.
1.329 s
OK
function result: 11
function result: 11
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:23:27 UTC,
java,
verify,
result: Failed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
//count=count+(b/a)*(a/k);
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
Example tests
1.
1.329 s
WRONG ANSWER,
got 2 expected 3
expand all
User tests
1.
1.329 s
OK
function result: 2
function result: 2
1.
1.327 s
OK
function result: 1
function result: 1
1.
1.330 s
OK
function result: 8
function result: 8
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:24:58 UTC,
java,
verify,
result: Failed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
//count=count+(b/a)*(a/k);
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
Example tests
1.
1.330 s
WRONG ANSWER,
got 2 expected 3
expand all
User tests
1.
1.173 s
OK
function result: 2
function result: 2
1.
1.344 s
OK
function result: 1
function result: 1
1.
1.339 s
OK
function result: 8
function result: 8
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:26:47 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.302 s
OK
function result: 3
function result: 3
1.
1.312 s
OK
function result: 1
function result: 1
1.
1.306 s
OK
function result: 9
function result: 9
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
Code: 06:27:10 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.328 s
OK
function result: 3
function result: 3
1.
1.327 s
OK
function result: 1
function result: 1
1.
1.305 s
OK
function result: 9
function result: 9
1.
1.326 s
OK
function result: 0
function result: 0
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
Code: 06:27:42 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0){
a=k;
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
Code: 06:29:14 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
/*if(a==0){
a=k;
count=1;
}*/
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.310 s
OK
function result: 3
function result: 3
1.
1.326 s
OK
function result: 1
function result: 1
1.
1.308 s
OK
function result: 9
function result: 9
1.
1.339 s
RUNTIME ERROR,
tested program terminated unexpectedly
stderr:
Exception in thread "main" java.lang.ArithmeticException: / by zero at Solution.solution(Solution.java:35) at wrapper.run(wrapper.java:42) at wrapper.main(wrapper.java:31)
1.
1.336 s
OK
function result: 1
function result: 1
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
Code: 06:29:54 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
if(a==0 && b==0){
count=1;
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.300 s
OK
function result: 3
function result: 3
1.
1.300 s
OK
function result: 1
function result: 1
1.
1.299 s
OK
function result: 9
function result: 9
1.
1.333 s
RUNTIME ERROR,
tested program terminated unexpectedly
stderr:
Exception in thread "main" java.lang.ArithmeticException: / by zero at Solution.solution(Solution.java:34) at wrapper.run(wrapper.java:42) at wrapper.main(wrapper.java:31)
1.
1.310 s
OK
function result: 1
function result: 1
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
Code: 06:30:36 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a==0 && b==0){
count=1;
}else if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
Code: 06:31:00 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a==0 && b==0){
count=1;
}else if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.328 s
OK
function result: 3
function result: 3
1.
1.338 s
OK
function result: 1
function result: 1
1.
1.328 s
OK
function result: 9
function result: 9
1.
1.340 s
OK
function result: 1
function result: 1
1.
1.338 s
OK
function result: 1
function result: 1
1.
1.338 s
OK
function result: 199
function result: 199
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
User test case 6:
[1, 199, 1]
Code: 06:31:34 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a==0 && b==0){
count=1;
}else if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.327 s
OK
function result: 3
function result: 3
1.
1.329 s
OK
function result: 1
function result: 1
1.
1.311 s
OK
function result: 9
function result: 9
1.
1.334 s
OK
function result: 1
function result: 1
1.
1.328 s
OK
function result: 1
function result: 1
1.
1.336 s
OK
function result: 199
function result: 199
1.
1.087 s
OK
function result: 201
function result: 201
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
User test case 6:
[1, 199, 1]
User test case 7:
[0, 200, 1]
Code: 06:32:00 UTC,
java,
verify,
result: Passed
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a==0 && b==0){
count=1;
}else if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}
Analysis
expand all
User tests
1.
1.323 s
OK
function result: 3
function result: 3
1.
1.317 s
OK
function result: 1
function result: 1
1.
1.316 s
OK
function result: 9
function result: 9
1.
1.321 s
OK
function result: 1
function result: 1
1.
1.322 s
OK
function result: 1
function result: 1
1.
1.312 s
OK
function result: 199
function result: 199
1.
1.321 s
OK
function result: 201
function result: 201
User test case 1:
[10, 14, 2]
User test case 2:
[11, 13, 12]
User test case 3:
[11, 19, 1]
User test case 4:
[0, 0, 1]
User test case 5:
[10, 10, 5]
User test case 6:
[1, 199, 1]
User test case 7:
[0, 200, 1]
Code: 06:32:18 UTC,
java,
final,
score:
100
// you can also use imports, for example:
// import java.util.*;
// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
class Solution {
public int solution(int A, int B, int K) {
// write your code in Java SE 8
long a=A;
long b=B;
long k=K;
long count=0;
long i=a%k;
//System.out.println(a+" "+b+" "+k);
if(i!=0){
a=a+Math.abs(i-k);
}
long j=b%k;
if(j!=0){
b=b-(Math.abs(j));
}
if(a!=b){
if(a%k==0) count=1;
count=count+(b-a)/k;
}else{
if(a==0 && b==0){
count=1;
}else if(a%k==0){
count=(b/a);
}else{
count=0;
}
}
return (int)count;
}
}Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(1)
expand all
Correctness tests
1.
1.342 s
OK
1.
1.353 s
OK
2.
1.341 s
OK
1.
1.349 s
OK
2.
1.348 s
OK
3.
1.353 s
OK
1.
1.358 s
OK
2.
1.346 s
OK
3.
0.969 s
OK
4.
0.915 s
OK
5.
0.905 s
OK
6.
0.980 s
OK
expand all
Performance tests
1.
1.191 s
OK
1.
1.110 s
OK
1.
1.056 s
OK
2.
1.100 s
OK
1.
1.083 s
OK
2.
1.006 s
OK
3.
1.339 s
OK
4.
1.341 s
OK