关于本计算器
Exact combinations nCr and permutations nPr as big integers.
组合排列
精确nCr与nPr。
输入计算参数
计算结果摘要
组合数120
排列数720
r!6
常见问题
nCr vs nPr?
Combinations ignore order; permutations count every ordering.
Exact?
BigInt arithmetic — no floating-point rounding.
Limit?
n up to 1000 with r ≤ n.