Merge pull request #884 from 0xff-dev/1781

Add solution and test-cases for problem 1781

Author: 6boris

leetcode/1701-1800/1781.Sum-of-Beauty-of-All-Substrings/README.md

@@ -1,28 +1,26 @@
 # [1781.Sum of Beauty of All Substrings][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
+The **beauty** of a string is the difference in frequencies between the most frequent and least frequent characters.
+
+- For example, the beauty of `"abaacc"` is `3 - 1 = 2`.
+
+Given a string `s`, return the sum of **beauty** of all of its substrings.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: s = "aabcb"
+Output: 5
+Explanation: The substrings with non-zero beauty are ["aab","aabc","aabcb","abcb","bcb"], each with beauty equal to 1.
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Sum of Beauty of All Substrings
-```go
 ```
-
+Input: s = "aabcbaa"
+Output: 17
+```
 
 ## 结语
 

leetcode/1701-1800/1781.Sum-of-Beauty-of-All-Substrings/Solution.go

@@ -1,5 +1,25 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(s string) int {
+	ans := 0
+	//ab,aa
+	for end := 2; end < len(s); end++ {
+		tmp := [26]int{}
+		tmp[s[end]-'a']++
+		a := 0
+		for pre := end - 1; pre >= 0; pre-- {
+			b := 0
+			tmp[s[pre]-'a']++
+			a = max(a, tmp[s[pre]-'a'])
+			for i := 0; i < 26; i++ {
+				if tmp[i] != 0 {
+					if b == 0 || b > tmp[i] {
+						b = tmp[i]
+					}
+				}
+			}
+			ans += a - b
+		}
+	}
+	return ans
 }

leetcode/1701-1800/1781.Sum-of-Beauty-of-All-Substrings/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 string
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "aabcb", 5},
+		{"TestCase2", "aabcbaa", 17},
 	}
 
 	//	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() {
 }