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排列与组合

计算任何 n 与 r 的 P(n,r) 排列数与 C(n,r) 组合数。

How to use

  1. Enter n (the total number of items) and r (how many you are choosing).
  2. Click Calculate. P(n,r) counts ordered arrangements; C(n,r) counts unordered selections.
  3. Use permutations when the order matters (e.g. race podium positions). Use combinations when it doesn't (e.g. lottery numbers).

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常见问题

Is this permutation and combination calculator free?
Yes, completely free with no signup and no usage limits.
Does my data leave my device?
No. All calculations run entirely in JavaScript inside your browser.
Does it work on mobile?
Yes. Works on iPhone Safari and Android Chrome without installing any app.

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