Add solution and test-cases for problem 3159

Author: 0xff-dev

leetcode/3101-3200/3159.Find-Occurrences-of-an-Element-in-an-Array/README.md

@@ -1,28 +1,38 @@
 # [3159.Find Occurrences of an Element in an Array][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 integer array `nums`, an integer array `queries`, and an integer `x`.
+
+For each `queries[i]`, you need to find the index of the `queries[i]th` occurrence of `x` in the `nums` array. If there are fewer than `queries[i]` occurrences of `x`, the answer should be -1 for that query.
+
+Return an integer array `answer` containing the answers to all queries.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
-```
+Input: nums = [1,3,1,7], queries = [1,3,2,4], x = 1
+
+Output: [0,-1,2,-1]
 
-## 题意
-> ...
+Explanation:
 
-## 题解
+For the 1st query, the first occurrence of 1 is at index 0.
+For the 2nd query, there are only two occurrences of 1 in nums, so the answer is -1.
+For the 3rd query, the second occurrence of 1 is at index 2.
+For the 4th query, there are only two occurrences of 1 in nums, so the answer is -1.
+```
+
+**Example 2:**
 
-### 思路1
-> ...
-Find Occurrences of an Element in an Array
-```go
 ```
+Input: nums = [1,2,3], queries = [10], x = 5
+
+Output: [-1]
 
+Explanation:
+
+For the 1st query, 5 doesn't exist in nums, so the answer is -1.
+```
 
 ## 结语
 

leetcode/3101-3200/3159.Find-Occurrences-of-an-Element-in-an-Array/Solution.go

@@ -1,5 +1,18 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(nums []int, queries []int, x int) []int {
+	indies := []int{}
+	for idx := 0; idx < len(nums); idx++ {
+		if nums[idx] == x {
+			indies = append(indies, idx)
+		}
+	}
+	ret := make([]int, len(queries))
+	for idx, q := range queries {
+		ret[idx] = -1
+		if q <= len(indies) {
+			ret[idx] = indies[q-1]
+		}
+	}
+	return ret
 }

leetcode/3101-3200/3159.Find-Occurrences-of-an-Element-in-an-Array/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
+		nums, queries []int
+		x             int
+		expect        []int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 3, 1, 7}, []int{1, 3, 2, 4}, 1, []int{0, -1, 2, -1}},
+		{"TestCase2", []int{1, 2, 3}, []int{10}, 5, []int{-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.nums, c.queries, c.x)
 			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 %v",
+					c.expect, got, c.nums, c.queries, c.x)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }