Solution of Frog Jumping Steps in php

A frog can jump up one step or two steps at a time. Find out how many jumping methods the frog has when jumping on a step of n level (different results are calculated according to different sequences).

Thoughts:

Find the law f (1) = 1 f (2) = 2 f (3) = 3 f (4) = 5 f (n) = f (n-1) + f (n-2) This is a Fibonacci sequence

2. Because when you adjust to the n step, the penultimate step can jump in one step, and the penultimate step can also jump in one step

Non-recursive version:

JumpFloor(target)

  if target==1 || target==2 return target

  jumpSum=0

  jump1=1

  jump2=2

  for i=3;i<target;i++

    jumpSum=jump1+jump2

    jump1=jump2

    jump2=jumpSum

  return jumpSum

function jumpFloor($number)

{

    if($number==1 || $number==2){

        return $number;

    }  

    $jumpSum=0;

    $jump1=1;

    $jump2=2;

    for($i=3;$i<=$number;$i++){

        $jumpSum=$jump1+$jump2;

        $jump1=$jump2;

        $jump2=$jumpSum;

    }  

    return $jumpSum;

}

$res=jumpFloor(10);

var_dump($res);

The above code examples can be tested locally. Thank you for your support of this site.