Merge pull request #1081 from 0xff-dev/2559

Add solution and test-cases for problem 2559

Author: 6boris

leetcode/2501-2600/2559.Count-Vowel-Strings-in-Ranges/README.md

@@ -0,0 +1,37 @@
+# [2559.Count Vowel Strings in Ranges][title]
+
+## Description
+You are given a **0-indexed** array of strings `words` and a 2D array of integers `queries`.
+
+Each query `queries[i] = [li, ri]` asks us to find the number of strings present in the range `li` to `ri` (both **inclusive**) of `words` that start and end with a vowel.
+
+Return an array `ans` of size `queries.length`, where `ans[i]` is the answer to the `ith` query.
+
+**Note** that the vowel letters are `'a'`, `'e'`, `'i'`, `'o'`, and `'u'`.
+
+**Example 1:**
+
+```
+Input: words = ["aba","bcb","ece","aa","e"], queries = [[0,2],[1,4],[1,1]]
+Output: [2,3,0]
+Explanation: The strings starting and ending with a vowel are "aba", "ece", "aa" and "e".
+The answer to the query [0,2] is 2 (strings "aba" and "ece").
+to query [1,4] is 3 (strings "ece", "aa", "e").
+to query [1,1] is 0.
+We return [2,3,0].
+```
+
+**Example 2:**
+
+```
+Input: words = ["a","e","i"], queries = [[0,2],[0,1],[2,2]]
+Output: [3,2,1]
+Explanation: Every string satisfies the conditions, so we return [3,2,1].
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
+
+[title]: https://leetcode.com/problems/count-vowel-strings-in-ranges
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2501-2600/2559.Count-Vowel-Strings-in-Ranges/Solution.go

@@ -1,5 +1,25 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func isVowel(b byte) bool {
+	return b == 'a' || b == 'e' || b == 'i' || b == 'o' || b == 'u'
+}
+
+func Solution(words []string, queries [][]int) []int {
+	count := make([]int, len(words))
+	pre := 0
+	for i, w := range words {
+		count[i] = pre
+		if isVowel(w[0]) && isVowel(w[len(w)-1]) {
+			count[i]++
+		}
+		pre = count[i]
+	}
+	ans := make([]int, len(queries))
+	for i, q := range queries {
+		ans[i] = count[q[1]]
+		if q[0] > 0 {
+			ans[i] -= count[q[0]-1]
+		}
+	}
+	return ans
 }

leetcode/2501-2600/2559.Count-Vowel-Strings-in-Ranges/Solution_test.go

@@ -9,31 +9,31 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name    string
+		words   []string
+		queries [][]int
+		expect  []int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []string{"aba", "bcb", "ece", "aa", "ee"}, [][]int{{0, 2}, {1, 4}, {1, 1}}, []int{2, 3, 0}},
+		{"TestCase2", []string{"a", "e", "i"}, [][]int{{0, 2}, {0, 1}, {2, 2}}, []int{3, 2, 1}},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.words, c.queries)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.words, c.queries)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }