摘要:
#include #include#include#include#include#include#includeusing namespace std;typedef long int64;int64 work(int64 n,int64 k){ if (k>n/2)k=n-k; int64 a=1,b=1; for (int i=1;iusing namespace std;int work(int n,int k){ return k==0?1:work(n,k-1)*(n-k+1)/k;}int main(){ int n,k; while (sca...
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