diff --git a/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/README.md b/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/README.md index ec6077aa8..c5fb4b615 100755 --- a/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/README.md +++ b/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/README.md @@ -1,28 +1,53 @@ # [3577.Count the Number of Computer Unlocking Permutations][title] -> [!WARNING|style:flat] -> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm) - ## Description +You are given an array `complexity` of length `n`. + +There are `n` **locked** computers in a room with labels from 0 to `n - 1`, each with its own **unique** password. The password of the computer `i` has a `complexity complexity[i]`. + +The password for the computer labeled 0 is **already** decrypted and serves as the root. All other computers must be unlocked using it or another previously unlocked computer, following this information: + +- You can decrypt the password for the computer `i` using the password for computer `j`, where `j` is **any** integer less than `i` with a lower complexity. (i.e. `j < i` and `complexity[j] < complexity[i]`) +- To decrypt the password for computer `i`, you must have already unlocked a computer `j` such that `j < i` and `complexity[j] < complexity[i]`. + +Find the number of permutations of `[0, 1, 2, ..., (n - 1)]` that represent a valid order in which the computers can be unlocked, starting from computer 0 as the only initially unlocked one. + +Since the answer may be large, return it **modulo** `10^9 + 7`. + +**Note** that the password for the computer **with label** 0 is decrypted, and not the computer with the first position in the permutation. **Example 1:** ``` -Input: a = "11", b = "1" -Output: "100" -``` +Input: complexity = [1,2,3] -## 题意 -> ... +Output: 2 -## 题解 +Explanation: + +The valid permutations are: + +[0, 1, 2] +Unlock computer 0 first with root password. +Unlock computer 1 with password of computer 0 since complexity[0] < complexity[1]. +Unlock computer 2 with password of computer 1 since complexity[1] < complexity[2]. +[0, 2, 1] +Unlock computer 0 first with root password. +Unlock computer 2 with password of computer 0 since complexity[0] < complexity[2]. +Unlock computer 1 with password of computer 0 since complexity[0] < complexity[1]. +``` + +**Example 2:** -### 思路1 -> ... -Count the Number of Computer Unlocking Permutations -```go ``` +Input: complexity = [3,3,3,4,4,4] +Output: 0 + +Explanation: + +There are no possible permutations which can unlock all computers. +``` ## 结语 diff --git a/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution.go b/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution.go index d115ccf5e..aedff6c6c 100644 --- a/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution.go +++ b/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution.go @@ -1,5 +1,17 @@ package Solution -func Solution(x bool) bool { - return x +func Solution(complexity []int) int { + n := len(complexity) + for i := 1; i < n; i++ { + if complexity[i] <= complexity[0] { + return 0 + } + } + + ans := 1 + mod := 1000000007 + for i := 2; i < n; i++ { + ans = ans * i % mod + } + return ans } diff --git a/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution_test.go b/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution_test.go index 14ff50eb4..b745eebb4 100644 --- a/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution_test.go +++ b/leetcode/3501-3600/3577.Count-the-Number-of-Computer-Unlocking-Permutations/Solution_test.go @@ -10,12 +10,11 @@ func TestSolution(t *testing.T) { // 测试用例 cases := []struct { name string - inputs bool - expect bool + inputs []int + expect int }{ - {"TestCase", true, true}, - {"TestCase", true, true}, - {"TestCase", false, false}, + {"TestCase1", []int{1, 2, 3}, 2}, + {"TestCase2", []int{3, 3, 3, 4, 4, 4}, 0}, } // 开始测试 @@ -30,10 +29,10 @@ func TestSolution(t *testing.T) { } } -// 压力测试 +// 压力测试 func BenchmarkSolution(b *testing.B) { } -// 使用案列 +// 使用案列 func ExampleSolution() { }