Merge pull request #864 from 0xff-dev/1542

Add solution and test-cases for problem 1542

leetcode/1501-1600/1542.Find-Longest-Awesome-Substring/README.md

@@ -1,28 +1,32 @@
 # [1542.Find Longest Awesome Substring][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 string `s`. An **awesome** substring is a non-empty substring of `s` such that we can make any number of swaps in order to make it a palindrome.
+
+Return the length of the maximum length **awesome substring** of `s`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: s = "3242415"
+Output: 5
+Explanation: "24241" is the longest awesome substring, we can form the palindrome "24142" with some swaps.
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Find Longest Awesome Substring
-```go
+```
+Input: s = "12345678"
+Output: 1
 ```
 
+**Example 3:**
+
+```
+Input: s = "213123"
+Output: 6
+Explanation: "213123" is the longest awesome substring, we can form the palindrome "231132" with some swaps.
+```
 
 ## 结语
 

leetcode/1501-1600/1542.Find-Longest-Awesome-Substring/Solution.go

@@ -1,5 +1,25 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(s string) int {
+	state := map[int]int{
+		0: -1,
+	}
+
+	mask := 0
+	ans := 0
+	for i := 0; i < len(s); i++ {
+		shift := s[i] - '0'
+		mask ^= (1 << shift)
+		if v, ok := state[mask]; ok {
+			ans = max(ans, i-v)
+		} else {
+			state[mask] = i
+		}
+		for j := 0; j < 10; j++ {
+			if v, ok := state[mask^(1<<j)]; ok {
+				ans = max(ans, i-v)
+			}
+		}
+	}
+	return ans
 }

leetcode/1501-1600/1542.Find-Longest-Awesome-Substring/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "3242415", 5},
+		{"TestCase2", "12345678", 1},
+		{"TestCase3", "213123", 6},
 	}
 
 	//	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() {
 }