Tasks Details
easy
1.
FrogJmp
Count minimal number of jumps from position X to Y.
Task Score
100%
Correctness
100%
Performance
100%
A small frog wants to get to the other side of the road. The frog is currently located at position X and wants to get to a position greater than or equal to Y. The small frog always jumps a fixed distance, D.
Count the minimal number of jumps that the small frog must perform to reach its target.
Write a function:
class Solution { public int solution(int X, int Y, int D); }
that, given three integers X, Y and D, returns the minimal number of jumps from position X to a position equal to or greater than Y.
For example, given:
X = 10 Y = 85 D = 30the function should return 3, because the frog will be positioned as follows:
- after the first jump, at position 10 + 30 = 40
- after the second jump, at position 10 + 30 + 30 = 70
- after the third jump, at position 10 + 30 + 30 + 30 = 100
Write an efficient algorithm for the following assumptions:
- X, Y and D are integers within the range [1..1,000,000,000];
- X ≤ Y.
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used Java 8
Time spent on task 8 minutes
Notes
not defined yet
Task timeline
Code: 12:54:30 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 X, int Y, int D) {
// write your code in Java SE 8
int diff=Y-X;
int div=diff/D;
System.out.println(div);
return 3;
}
}
Analysis
Code: 12:54:47 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 X, int Y, int D) {
// write your code in Java SE 8
double diff=Y-X;
double div=diff/D;
System.out.println(div);
return 3;
}
}
Analysis
Code: 12:55:04 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 X, int Y, int D) {
// write your code in Java SE 8
double diff=Y-X;
double div=diff/D;
System.out.println((int)div);
return 3;
}
}
Analysis
Code: 12:55:14 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 X, int Y, int D) {
// write your code in Java SE 8
double diff=Y-X;
double div=diff/D;
System.out.println(div);
return 3;
}
}
Analysis
Code: 12:55:47 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 X, int Y, int D) {
// write your code in Java SE 8
double diff=Y-X;
double div=diff/D;
System.out.println((Integer)div);
return 3;
}
}
Analysis
Compile error
Solution.java:12: error: incompatible types: double cannot be converted to Integer
System.out.println((Integer)div);
^
1 error
Code: 12:56:01 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 X, int Y, int D) {
// write your code in Java SE 8
double diff=Y-X;
double div=diff/D;
System.out.println((float)div);
return 3;
}
}
Analysis
Code: 12:57:36 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 X, int Y, int D) {
// write your code in Java SE 8
int diff=Y-X;
int div=diff/D;
int sum=X+div*D;
if(Y>sum) div++;
return div;
}
}
Analysis
Code: 12:58:15 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 X, int Y, int D) {
// write your code in Java SE 8
int diff=Y-X;
int div=diff/D;
int sum=X+div*D;
if(Y>sum) div++;
return div;
}
}
User test case 1:
[1, 3, 1]
Analysis
Code: 12:58:51 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 X, int Y, int D) {
// write your code in Java SE 8
int diff=Y-X;
int div=diff/D;
int sum=X+div*D;
if(Y>sum) div++;
return div;
}
}
User test case 1:
[1, 3, 1]
Analysis
Code: 12:58:59 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 X, int Y, int D) {
// write your code in Java SE 8
int diff=Y-X;
int div=diff/D;
int sum=X+div*D;
if(Y>sum) div++;
return div;
}
}Analysis summary
The solution obtained perfect score.
Analysis
Detected time complexity:
O(1)
expand all
Correctness tests
1.
1.348 s
OK
2.
1.338 s
OK
1.
1.332 s
OK
2.
1.339 s
OK
1.
1.349 s
OK
2.
1.322 s
OK
1.
1.341 s
OK