1.我们先输入n m的数字,因为n!/(n-m)!的阶乘。即4!=4*3*2*1,2!=2*1,4!/2!=12.或者4!=4*3*2!。
#include<sdtio.h>
int main()
{int n = 0;int m = 0;long long a = 1;while ((scanf_s("%d%d",&n,&m))!=EOF){for (int i = n; i > n-m; i--) {a = a * i;}printf("%lld\n", a);}return 0;
}
1.我们先输入n m的数字,因为n!/(n-m)!的阶乘。即4!=4*3*2*1,2!=2*1,4!/2!=12.或者4!=4*3*2!。
#include<sdtio.h>
int main()
{int n = 0;int m = 0;long long a = 1;while ((scanf_s("%d%d",&n,&m))!=EOF){for (int i = n; i > n-m; i--) {a = a * i;}printf("%lld\n", a);}return 0;
}