Android 3x3 数字矩阵上可能的模式
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patterns possible on 3x3 matrix of numbers
提问by user1502308
Possible Duplicate:
android lock password combinations
可能重复：
android 锁密码组合
Respected sir, I came across a question which asked for finding all the unique pattern possible given a 3x3 matrix with numbers from 1-9. which is same as android lock screen. Can you help me how to find it ?? I was thinking can we use floyd warshall for this and increment count whenever the value changes in the subsequent matrix??
尊敬的先生，我遇到了一个问题，该问题要求在给定 1-9 数字的 3x3 矩阵的情况下找到所有可能的独特模式。这与安卓锁屏相同。你能帮我如何找到它吗？？我在想我们可以为此使用 floyd warshall 并在后续矩阵中的值发生变化时增加计数吗？？
回答by Raghav Sood
Combinations of the Android pattern lock screen would not be from 1-9. Instead, they would be 4-9, as the lock pattern needs a minimum of four inputs, and anything below that is invalid (at least 2.3 onwards. I believe 2.2 and below allowed 3 point locks). Here's the breakdown of the combinations:
Android 图案锁屏的组合不会是 1-9。相反，它们将是 4-9，因为锁定模式至少需要四个输入，并且任何低于该值的输入都是无效的（至少 2.3 起。我相信 2.2 及以下允许 3 点锁定）。以下是组合的细分：
Moves = 4, combinations = 1624
Moves = 5, combinations = 7152
Moves = 6, combinations = 26016
Moves = 7, combinations = 72912
Moves = 8, combinations = 140704
Moves = 9, combinations = 140704
Total possibilities: 1624 + 7152 + 26016 + 72912 + 140704 + 140704 = 389112
A complete breakdown of the Math behind this given by a Google Engineer can be found here.
谷歌工程师给出的这背后的数学的完整细分可以在这里找到。
