Add solution and test-cases for problem 2416

leetcode/2401-2500/2416.Sum-of-Prefix-Scores-of-Strings/README.md

@@ -1,28 +1,45 @@
 # [2416.Sum of Prefix Scores of Strings][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 `words` of size `n` consisting of **non-empty** strings.
+
+We define the **score** of a string `word` as the **number** of strings `words[i]` such that `word` is a **prefix** of `words[i]`.
+
+- For example, if `words = ["a", "ab", "abc", "cab"]`, then the score of `"ab"` is `2`, since `"ab"` is a prefix of both `"ab"` and `"abc"`.
+
+Return an array `answer` of size `n` where `answer[i]` is the **sum** of scores of every **non-empty** prefix of `words[i]`.
+
+**Note** that a string is considered as a prefix of itself.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: words = ["abc","ab","bc","b"]
+Output: [5,4,3,2]
+Explanation: The answer for each string is the following:
+- "abc" has 3 prefixes: "a", "ab", and "abc".
+- There are 2 strings with the prefix "a", 2 strings with the prefix "ab", and 1 string with the prefix "abc".
+The total is answer[0] = 2 + 2 + 1 = 5.
+- "ab" has 2 prefixes: "a" and "ab".
+- There are 2 strings with the prefix "a", and 2 strings with the prefix "ab".
+The total is answer[1] = 2 + 2 = 4.
+- "bc" has 2 prefixes: "b" and "bc".
+- There are 2 strings with the prefix "b", and 1 string with the prefix "bc".
+The total is answer[2] = 2 + 1 = 3.
+- "b" has 1 prefix: "b".
+- There are 2 strings with the prefix "b".
+The total is answer[3] = 2.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Sum of Prefix Scores of Strings
-```go
 ```
-
+Input: words = ["abcd"]
+Output: [4]
+Explanation:
+"abcd" has 4 prefixes: "a", "ab", "abc", and "abcd".
+Each prefix has a score of one, so the total is answer[0] = 1 + 1 + 1 + 1 = 4.
+```
 
 ## 结语
 

leetcode/2401-2500/2416.Sum-of-Prefix-Scores-of-Strings/Solution.go

@@ -1,5 +1,48 @@
 package Solution
 
-func Solution(x bool) bool {
+type trieNode2416 struct {
+	count int
+	child [26]*trieNode2416
+}
+
+func (r *trieNode2416) insert(word string) {
+	walker := r
+	for i := range word {
+		index := word[i] - 'a'
+		if walker.child[index] == nil {
+			walker.child[index] = &trieNode2416{}
+		}
+		walker.child[index].count++
+		walker = walker.child[index]
+	}
+}
+
+func (r *trieNode2416) score(word string) int {
+	walker := r
+	x := 0
+	for i := range word {
+		index := word[i] - 'a'
+		x += walker.child[index].count
+		walker = walker.child[index]
+	}
 	return x
 }
+func Solution(words []string) []int {
+	ans := make([]int, len(words))
+	tree := &trieNode2416{}
+	for _, w := range words {
+		tree.insert(w)
+	}
+	d := make(map[string]int)
+	for i, w := range words {
+		if v, ok := d[w]; ok {
+			ans[i] = v
+			continue
+		}
+		score := tree.score(w)
+		ans[i] = score
+		d[w] = score
+	}
+
+	return ans
+}

leetcode/2401-2500/2416.Sum-of-Prefix-Scores-of-Strings/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", []string{"abc", "ab", "bc", "b"}, []int{5, 4, 3, 2}},
+		{"TestCase2", []string{"abcd"}, []int{4}},
 	}
 
 	//	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() {
 }