题解 | #牛牛的排列数#
牛牛的排列数
http://www.nowcoder.com/practice/9ca1c236cdbf46da9e08e1f510808625
int main() {
int n, m;
scanf("%d %d", &n, &m);
int sum = 1;
for (int i = 1; i <= m; i++) {
sum *= n - i + 1;
}
printf("%d", sum);
return 0;
}
