Editorial for ICPC NWERC 2011 A - Binomial Coefficients
Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
- Find such that
- Only look for solutions with and count twice if necessary
- Approach 1:
- Loop over from to
- Binary search for
- Approach 2:
- For , solution is
- For , solve
- For , loop over until
- Be really careful with overflows!
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