nyoj1131买水果

#include <stdio.h>int main(){long long t,a,b,sum1,sum2,j,i;scanf("%lld",&t);while(t--){scanf("%lld %lld",&a,&b);if(a-b<b)b=a-b;sum1=sum2=1;for(j=a,i=1;i<=b;i++,j--){if(j%i==0||sum1%i==0){sum1=sum1*j/i;continue;}if(sum1%sum2==0)sum1=sum1/sum2,sum2=1;sum1=sum1*j;sum2=sum2*i;}printf("%lld\n",sum1/sum2);}return 0;}