Test results - Codility

Tasks Details

medium

1. CommonPrimeDivisors

Check whether two numbers have the same prime divisors.

Task Score

100%

Correctness

100%

Performance

100%

A prime is a positive integer X that has exactly two distinct divisors: 1 and X. The first few prime integers are 2, 3, 5, 7, 11 and 13.

A prime D is called a prime divisor of a positive integer P if there exists a positive integer K such that D * K = P. For example, 2 and 5 are prime divisors of 20.

You are given two positive integers N and M. The goal is to check whether the sets of prime divisors of integers N and M are exactly the same.

For example, given:

N = 15 and M = 75, the prime divisors are the same: {3, 5};

N = 10 and M = 30, the prime divisors aren't the same: {2, 5} is not equal to {2, 3, 5};

N = 9 and M = 5, the prime divisors aren't the same: {3} is not equal to {5}.

Write a function:

class Solution { public int solution(int[] A, int[] B); }

that, given two non-empty arrays A and B of Z integers, returns the number of positions K for which the prime divisors of A[K] and B[K] are exactly the same.

For example, given:

A[0] = 15 B[0] = 75 A[1] = 10 B[1] = 30 A[2] = 3 B[2] = 5

the function should return 1, because only one pair (15, 75) has the same set of prime divisors.

Write an efficient algorithm for the following assumptions:

Z is an integer within the range [1..6,000];

each element of arrays A and B is an integer within the range [1..2,147,483,647].

Solution

Programming language used Java 8

Time spent on task 5 minutes

Notes

not defined yet

Task timeline

Code: 05:17:55 UTC, java, autosave

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// 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) {
        // write your code in Java SE 8
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:18:26 UTC, java, autosave

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if () {
                
            }
        }
        return result;
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:18:56 UTC, java, autosave

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if () {
                result++;
            }
        }
        return result;
    }
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:19:27 UTC, java, autosave

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if () {
                result++;
            }
        }
        return result;
    }
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        int quotient1 = 0;
        while (quotient1 != 1) {
            quotient1 = getGcd(num, gcd);
            num /= quotient1;
        }

    }
    rp
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:19:40 UTC, java, autosave

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if () {
                result++;
            }
        }
        return result;
    }
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        int quotient1 = 0;
        while (quotient1 != 1) {
            quotient1 = getGcd(num, gcd);
            num /= quotient1;
        }

    }
    private int getDivisor() {
        int quotient
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:20:10 UTC, java, autosave

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if () {
                result++;
            }
        }
        return result;
    }
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        int quotient1 = 0;
        while (quotient1 != 1) {
            quotient1 = getGcd(num, gcd);
            num /= quotient1;
        }

    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:20:40 UTC, java, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if () {
                result++;
            }
        }
        return result;
    }
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2);
    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:20:55 UTC, java, autosave

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if (isSameDivisors(A[idx], B[idx])) {
                result++;
            }
        }
        return result;
    }
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2);
    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Code: 05:21:12 UTC, java, verify, result: Failed

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if (isSameDivisors(A[idx], B[idx])) {
                result++;
            }
        }
        return result;
    }
    // Check whether the sets of prime divisors of integers N and M are exactly the same.
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2);
    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    // Euclidean algorithm.
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Analysis

Compile error

Solution.java:20: error: bad operand types for binary operator '&&'
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2);
                                          ^
  first type:  boolean
  second type: int
1 error

Code: 05:21:24 UTC, java, verify, result: Passed

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// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if (isSameDivisors(A[idx], B[idx])) {
                result++;
            }
        }
        return result;
    }
    // Check whether the sets of prime divisors of integers N and M are exactly the same.
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2) == 1;
    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    // Euclidean algorithm.
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Analysis

expand all Example tests

▶

example
example test

✔

0.008 s

Code: 05:21:30 UTC, java, verify, result: Passed

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if (isSameDivisors(A[idx], B[idx])) {
                result++;
            }
        }
        return result;
    }
    // Check whether the sets of prime divisors of integers N and M are exactly the same.
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2) == 1;
    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    // Euclidean algorithm.
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Analysis

expand all Example tests

▶

example
example test

✔

0.008 s

Code: 05:21:34 UTC, java, final, score: 100

show code in pop-up

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

// 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 result = 0;
        for (int idx = 0; idx < A.length; idx++) {
            if (isSameDivisors(A[idx], B[idx])) {
                result++;
            }
        }
        return result;
    }
    // Check whether the sets of prime divisors of integers N and M are exactly the same.
    private boolean isSameDivisors(int num1, int num2) {
        int gcd = getGcd(num1, num2);
        return getDivisor(gcd, num1) == 1 && getDivisor(gcd, num2) == 1;
    }
    private int getDivisor(int gcd, int num) {
        int quotient = 0;
        while (quotient != 1) {
            quotient = getGcd(num, gcd);
            num /= quotient;
        }
        return num;
    }
    // Euclidean algorithm.
    private int getGcd(int num1, int num2) {
        if (num1 % num2 == 0) {
            return num2;
        } else {
            return getGcd(num2, num1 % num2);
        }
    }
}

Analysis summary

The solution obtained perfect score.

Analysis

Detected time complexity:

O(Z * log(max(A) + max(B))**2)

expand all Example tests

▶

example
example test

✔

0.004 s

expand all Correctness tests

▶

extreme
extreme test with small values

✔

0.008 s

▶

simple_1
simple test with small values

✔

0.008 s

▶

simple_2
simple test with small values

✔

0.008 s

▶

primes
powers of primes

✔

0.008 s

▶

small_primes
small primes

✔

0.008 s

▶

small_all_pairs
all pairs 1-10, length = 100

✔

0.008 s

▶

small_random
small random test, length = 100

✔

0.004 s

expand all Performance tests

▶

large_all_pairs
all pairs 1-70, length = ~5,000

✔

0.028 s

▶

large_random
large random tests, length = ~6,000

✔

0.060 s

0.064 s

▶

many_factors
factorial test

✔

0.064 s

▶

many_factors2
factorial test

✔

0.060 s

▶

big_powers
powers of 2 and 3

✔

0.056 s

▶

extreme_maximal
extreme test with maximal values

✔

0.044 s