Benchmark: Compare GCD - MeasureThat.net

Script Preparation code:

function greatestCommonDivisor(a, b){
  var divisor = 2, 
      greatestDivisor = 1;

  //if u pass a -ve number this will not work. fix it dude!!
  if (a < 2 || b < 2)
     return 1;
  
  while(a >= divisor && b >= divisor){
   if(a %divisor == 0 && b% divisor ==0){
      greatestDivisor = divisor;      
    }
   divisor++;
  }
  return greatestDivisor;
}

function gcd(a,b){
    var divisor = a < b ? a : b;  	
    
    if(a < 2 || b < 2){
        return 1;
    }
    
    while(divisor > 0){
        if(a % divisor === 0 && b % divisor === 0){
            return divisor;
        }
        divisor--;
    }
}

Tests:

Bottom Up
greatestCommonDivisor(1012, 10580);
Top Down
gcd(1012, 10580);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Bottom Up
Top Down

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the details of this benchmark.

**Benchmark Test**

The provided JSON represents a JavaScript microbenchmark test for comparing two different algorithms to calculate the greatest common divisor (GCD) of two numbers: `greatestCommonDivisor` and `gcd`. The goal is to compare the performance of these two functions on the same input values.

**Script Preparation Code**

Both functions, `greatestCommonDivisor` and `gcd`, take two arguments `a` and `b`. They perform a similar calculation:

*   Initialize variables `divisor` and `greatestDivisor`.
*   If either `a` or `b` is less than 2, return 1 (since GCD of two numbers with at least one being greater than 1 must be at least 1).
*   Iterate from 2 to a maximum possible divisor:
    *   Check if both `a` and `b` can be divided by the current `divisor`.
        +   If so, update `greatestDivisor`.
    *   Increment the `divisor`.
*   Return the final calculated GCD.

**Html Preparation Code**

Since there is no HTML preparation code provided, we will assume that it's empty or not applicable to this specific benchmark.

**Individual Test Cases**

There are two individual test cases:

1.  **Bottom Up**: This test case uses the `greatestCommonDivisor` function with input values (1012 and 10580).
2.  **Top Down**: This test case uses the `gcd` function with the same input values.

**Library Usage**

No external libraries are used in this benchmark.

**Special JS Features/Syntax**

There doesn't seem to be any special JavaScript features or syntax being tested in this benchmark.

**Options Compared**

The two main options compared are:

1.  **Top Down**: The `gcd` function.
2.  **Bottom Up**: The `greatestCommonDivisor` function.

**Pros and Cons of Each Approach:**

*   **Top Down (GCD)**:
    *   Pros:
        -   Simpler code structure.
        -   Easier to implement.
    *   Cons:
        -   May have a higher number of iterations due to the `while` loop condition being stricter.
*   **Bottom Up (Greatest Common Divisor)**:
    -   Pros:
        -   More efficient, as it starts with a smaller divisor and increments it.
    *   Cons:
        -   Code structure might be more complex.

**Other Considerations:**

-   Both functions are tested on the same input values to ensure fair comparison.
-   The benchmark uses Chrome 53 on Windows 8.1 for execution, which may not reflect performance in other browsers or environments.

**Alternatives:**

If you want to test alternative GCD algorithms, consider using:

*   **Euclidean Algorithm**: A widely used algorithm for calculating the greatest common divisor, known for its efficiency and simplicity.
*   **Binary GCD**: An optimized algorithm that uses bitwise operations to calculate the GCD in a single loop.

You can implement these alternatives and compare their performance against the `greatestCommonDivisor` and `gcd` functions using MeasureThat.net or other benchmarking tools.

Related benchmarks:

Compare GCD (version: 0)

Compare GCD

Comparing performance of: Bottom Up vs Top Down

Created: 9 years ago by: Guest

Jump to the latest result

Bottom Up

Top Down

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):