vaps2012000's blog

next number
By vaps2012000, history, 3 years ago, In English

how to find the next number which has all different digits and greater than the given number N? Like if N=2000 then the answer is 2013. how to approach this problem. where 1<=N<=10^16

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3 years ago, # |
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The answer will not exits if it has more than 10 digits. for less than or equal to 10 digits you can form all the permutations.

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3 years ago, # |
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If you code in Python, you could use a dictionary that keeps adding the value TRUE for every digit of the number in consideration. After all the digits of the number have been traversed AND if a digit is found to already have a value TRUE in dictionary, clear the dictionary and move on to the next number. When a number with all digits distinct is found, break out of the loop.

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    3 years ago, # ^ |
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    I think that's working upto 10^8 ,but my need is upto 10^16.

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      3 years ago, # ^ |
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      But how can it be upto 10^16 ? Digits will starting repeating in every number after 9876543210. :/

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3 years ago, # |
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Could you please post a link to this problem? Thanks!

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3 years ago, # |
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The question link u posted doesnt have such big limits on n..

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3 years ago, # |
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Here's my greedy approach sorry abit messy that I believe will work for any number. The idea is:

  • ans cannot exceed 9876543210

  • start from left to right and when you find the digit that occurred before increase it, if it's 9 in increasing it will genereate a carry which which we have to add toward left.

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