Test results - Codility

Tasks Details

easy

1. FrogJmp

Count minimal number of jumps from position X to Y.

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 = 30

the 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.

Solution

Programming language used Java 8

Time spent on task 6 minutes

Notes

not defined yet

Task timeline

Code: 11:01:16 UTC, java, verify, result: Passed

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

// 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 mod = (Y - X) % D;
        int res = (Y-X)/D;
        if((Y-X) % D == 0)
            return res;
        else
            return res + 1;
        
    }
}

Analysis

▶

example
example test

✔

Code: 11:01:32 UTC, java, verify, result: Passed

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

// 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 mod = (Y - X) % D;
        int res = (Y-X)/D;
        if((Y-X) % D == 0)
            return res;
        else
            return res + 1;
        
    }
}

Analysis

▶

example
example test

✔

Code: 11:01:41 UTC, java, final, score: 100

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

// 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 mod = (Y - X) % D;
        int res = (Y-X)/D;
        if((Y-X) % D == 0)
            return res;
        else
            return res + 1;
        
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(1)

▶

example
example test

✔

▶

simple1
simple test

✔

▶

simple2

✔

▶

extreme_position
no jump needed

✔

▶

small_extreme_jump
one big jump

✔

▶

many_jump1
many jumps, D = 2

✔

▶

many_jump2
many jumps, D = 99

✔

▶

many_jump3
many jumps, D = 1283

✔

▶

big_extreme_jump
maximal number of jumps

✔

▶

small_jumps
many small jumps

✔