1443: Binomial Showdown
内存限制:128 MB
时间限制:1.000 S
评测方式:文本比较
命题人:
提交:28
解决:9
题目描述
In how many ways can you choose k elements out of n elements, not taking order into account?
Write a program to compute this number.
输入
The input will contain one or more test cases.
Each test case consists of one line containing two integers n (n>=1) and k (0<=k<=n).
Input is terminated by two zeroes for n and k.
输出
For each test case, print one line containing the required number. This number will always fit into an integer, i.e. it will be less than 231.
Warning: Don‘t underestimate the problem. The result will fit into an integer - but if all intermediate results arising during the computation will also fit into an integer depends on your algorithm. The test cases will go to the limit.
样例输入 复制
4 2
10 5
49 6
0 0
样例输出 复制
6
252
13983816
提示
练习赛8-D