Merge pull request #1024 from 0xff-dev/3011

Add solution and test-cases for problem 3011

Author: 6boris

leetcode/3001-3100/3011.Find-if-Array-Can-Be-Sorted/README.md

@@ -1,28 +1,42 @@
 # [3011.Find if Array Can Be Sorted][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 a **0-indexed** array of **positive** integers `nums`.
+
+In one **operation**, you can swap any two **adjacent** elements if they have the **same** number of `set bits`. You are allowed to do this operation **any** number of times (**including zero**).
+
+Return `true` if you can sort the array, else return `false`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: nums = [8,4,2,30,15]
+Output: true
+Explanation: Let's look at the binary representation of every element. The numbers 2, 4, and 8 have one set bit each with binary representation "10", "100", and "1000" respectively. The numbers 15 and 30 have four set bits each with binary representation "1111" and "11110".
+We can sort the array using 4 operations:
+- Swap nums[0] with nums[1]. This operation is valid because 8 and 4 have one set bit each. The array becomes [4,8,2,30,15].
+- Swap nums[1] with nums[2]. This operation is valid because 8 and 2 have one set bit each. The array becomes [4,2,8,30,15].
+- Swap nums[0] with nums[1]. This operation is valid because 4 and 2 have one set bit each. The array becomes [2,4,8,30,15].
+- Swap nums[3] with nums[4]. This operation is valid because 30 and 15 have four set bits each. The array becomes [2,4,8,15,30].
+The array has become sorted, hence we return true.
+Note that there may be other sequences of operations which also sort the array.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Find if Array Can Be Sorted
-```go
 ```
+Input: nums = [1,2,3,4,5]
+Output: true
+Explanation: The array is already sorted, hence we return true.
+```
+
+**Example 3:**
 
+```
+Input: nums = [3,16,8,4,2]
+Output: false
+Explanation: It can be shown that it is not possible to sort the input array using any number of operations.
+```
 
 ## 结语
 

leetcode/3001-3100/3011.Find-if-Array-Can-Be-Sorted/Solution.go

@@ -1,5 +1,34 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func countOfOne3011(n int) int {
+	c := 0
+	for n != 0 {
+		c++
+		n = n & (n - 1)
+	}
+	return c
+}
+
+func Solution(nums []int) bool {
+	ma, mi := nums[0], nums[0]
+	cur := countOfOne3011(nums[0])
+	list := make([][2]int, 0)
+	for i := 1; i < len(nums); i++ {
+		now := countOfOne3011(nums[i])
+		if now == cur {
+			ma = max(ma, nums[i])
+			mi = min(mi, nums[i])
+			continue
+		}
+		list = append(list, [2]int{ma, mi})
+		cur = now
+		ma, mi = nums[i], nums[i]
+	}
+	list = append(list, [2]int{ma, mi})
+	for i := 1; i < len(list); i++ {
+		if list[i][1] <= list[i-1][0] {
+			return false
+		}
+	}
+	return true
 }

leetcode/3001-3100/3011.Find-if-Array-Can-Be-Sorted/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
+		inputs []int
 		expect bool
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{8, 4, 2, 30, 15}, true},
+		{"TestCase2", []int{1, 2, 3, 4, 5}, true},
+		{"TestCase3", []int{3, 16, 8, 4, 3}, false},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ 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() {
 }