Hill climber expected number of steps












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Let's say you're trying to climb a hill with $k$ steps and you have $frac{1}{2}$ chance of climbing one step and $frac{1}{2}$ chance of falling back to the beginning of the hill. I am trying to find the expected number of steps to reach the top of the hill. After reasoning, it's clear that a misstep doubles the number of steps and a correct step increments the total number of steps. I'm not sure how to proceed, given that it's conceivable to get stuck in a potentially infinite loop of stepping up and then falling.










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  • 2




    $begingroup$
    Equivalent to this problem, generalized: math.stackexchange.com/questions/364038/…
    $endgroup$
    – T. Fo
    Jan 16 at 0:56
















0












$begingroup$


Let's say you're trying to climb a hill with $k$ steps and you have $frac{1}{2}$ chance of climbing one step and $frac{1}{2}$ chance of falling back to the beginning of the hill. I am trying to find the expected number of steps to reach the top of the hill. After reasoning, it's clear that a misstep doubles the number of steps and a correct step increments the total number of steps. I'm not sure how to proceed, given that it's conceivable to get stuck in a potentially infinite loop of stepping up and then falling.










share|cite|improve this question









$endgroup$








  • 2




    $begingroup$
    Equivalent to this problem, generalized: math.stackexchange.com/questions/364038/…
    $endgroup$
    – T. Fo
    Jan 16 at 0:56














0












0








0





$begingroup$


Let's say you're trying to climb a hill with $k$ steps and you have $frac{1}{2}$ chance of climbing one step and $frac{1}{2}$ chance of falling back to the beginning of the hill. I am trying to find the expected number of steps to reach the top of the hill. After reasoning, it's clear that a misstep doubles the number of steps and a correct step increments the total number of steps. I'm not sure how to proceed, given that it's conceivable to get stuck in a potentially infinite loop of stepping up and then falling.










share|cite|improve this question









$endgroup$




Let's say you're trying to climb a hill with $k$ steps and you have $frac{1}{2}$ chance of climbing one step and $frac{1}{2}$ chance of falling back to the beginning of the hill. I am trying to find the expected number of steps to reach the top of the hill. After reasoning, it's clear that a misstep doubles the number of steps and a correct step increments the total number of steps. I'm not sure how to proceed, given that it's conceivable to get stuck in a potentially infinite loop of stepping up and then falling.







algorithms recursion






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share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 16 at 0:52









faeophytafaeophyta

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  • 2




    $begingroup$
    Equivalent to this problem, generalized: math.stackexchange.com/questions/364038/…
    $endgroup$
    – T. Fo
    Jan 16 at 0:56














  • 2




    $begingroup$
    Equivalent to this problem, generalized: math.stackexchange.com/questions/364038/…
    $endgroup$
    – T. Fo
    Jan 16 at 0:56








2




2




$begingroup$
Equivalent to this problem, generalized: math.stackexchange.com/questions/364038/…
$endgroup$
– T. Fo
Jan 16 at 0:56




$begingroup$
Equivalent to this problem, generalized: math.stackexchange.com/questions/364038/…
$endgroup$
– T. Fo
Jan 16 at 0:56










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