Is there a way to reverse the Chinese Remainder Theorem? What extra information do we need?











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Dear math stackexchange community,



Given a list of numbers < N, after generating the Chinese Remainder, is there a way to get back to the same list of numbers?



Example:



N = 100



List of numbers = [32, 11, 57, 12] (all below N)



For Chinese Remainder we need pairwise coprimes, so I use a list of primes < N. Because a list of primes is automatically pairwise coprimes...



Primes = [2, 3, 5, 7] = a



List of remainder = [32 % 2, 11 % 3, 57 % 5, 12 % 7] = [0, 2, 2, 5] = m



Given that we know [a] and [m] we can find the lowest Chinese Remainder: 152



We can double check this result:




  • 152 % 2 = 0

  • 152 % 3 = 2

  • 152 % 5 = 2

  • 152 % 7 = 5


So just by knowing the number 152, we know the sets of remainders for the original list, what extra information do I need to find the original list of numbers?



(current idea is to generate all possible sequences that fit the prerequisites of [m] and use a number for the index within that sequence...) But maybe I'm missing something, any advice or suggestions would be more than welcome!










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  • You need all the residues for all the numbers. Then, you can recover the original numbers.
    – Peter
    Nov 21 at 19:05















up vote
0
down vote

favorite
1












Dear math stackexchange community,



Given a list of numbers < N, after generating the Chinese Remainder, is there a way to get back to the same list of numbers?



Example:



N = 100



List of numbers = [32, 11, 57, 12] (all below N)



For Chinese Remainder we need pairwise coprimes, so I use a list of primes < N. Because a list of primes is automatically pairwise coprimes...



Primes = [2, 3, 5, 7] = a



List of remainder = [32 % 2, 11 % 3, 57 % 5, 12 % 7] = [0, 2, 2, 5] = m



Given that we know [a] and [m] we can find the lowest Chinese Remainder: 152



We can double check this result:




  • 152 % 2 = 0

  • 152 % 3 = 2

  • 152 % 5 = 2

  • 152 % 7 = 5


So just by knowing the number 152, we know the sets of remainders for the original list, what extra information do I need to find the original list of numbers?



(current idea is to generate all possible sequences that fit the prerequisites of [m] and use a number for the index within that sequence...) But maybe I'm missing something, any advice or suggestions would be more than welcome!










share|cite|improve this question






















  • You need all the residues for all the numbers. Then, you can recover the original numbers.
    – Peter
    Nov 21 at 19:05













up vote
0
down vote

favorite
1









up vote
0
down vote

favorite
1






1





Dear math stackexchange community,



Given a list of numbers < N, after generating the Chinese Remainder, is there a way to get back to the same list of numbers?



Example:



N = 100



List of numbers = [32, 11, 57, 12] (all below N)



For Chinese Remainder we need pairwise coprimes, so I use a list of primes < N. Because a list of primes is automatically pairwise coprimes...



Primes = [2, 3, 5, 7] = a



List of remainder = [32 % 2, 11 % 3, 57 % 5, 12 % 7] = [0, 2, 2, 5] = m



Given that we know [a] and [m] we can find the lowest Chinese Remainder: 152



We can double check this result:




  • 152 % 2 = 0

  • 152 % 3 = 2

  • 152 % 5 = 2

  • 152 % 7 = 5


So just by knowing the number 152, we know the sets of remainders for the original list, what extra information do I need to find the original list of numbers?



(current idea is to generate all possible sequences that fit the prerequisites of [m] and use a number for the index within that sequence...) But maybe I'm missing something, any advice or suggestions would be more than welcome!










share|cite|improve this question













Dear math stackexchange community,



Given a list of numbers < N, after generating the Chinese Remainder, is there a way to get back to the same list of numbers?



Example:



N = 100



List of numbers = [32, 11, 57, 12] (all below N)



For Chinese Remainder we need pairwise coprimes, so I use a list of primes < N. Because a list of primes is automatically pairwise coprimes...



Primes = [2, 3, 5, 7] = a



List of remainder = [32 % 2, 11 % 3, 57 % 5, 12 % 7] = [0, 2, 2, 5] = m



Given that we know [a] and [m] we can find the lowest Chinese Remainder: 152



We can double check this result:




  • 152 % 2 = 0

  • 152 % 3 = 2

  • 152 % 5 = 2

  • 152 % 7 = 5


So just by knowing the number 152, we know the sets of remainders for the original list, what extra information do I need to find the original list of numbers?



(current idea is to generate all possible sequences that fit the prerequisites of [m] and use a number for the index within that sequence...) But maybe I'm missing something, any advice or suggestions would be more than welcome!







number-theory prime-numbers modular-arithmetic information-theory chinese-remainder-theorem






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asked Nov 21 at 12:20









Eli

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  • You need all the residues for all the numbers. Then, you can recover the original numbers.
    – Peter
    Nov 21 at 19:05


















  • You need all the residues for all the numbers. Then, you can recover the original numbers.
    – Peter
    Nov 21 at 19:05
















You need all the residues for all the numbers. Then, you can recover the original numbers.
– Peter
Nov 21 at 19:05




You need all the residues for all the numbers. Then, you can recover the original numbers.
– Peter
Nov 21 at 19:05















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