Add solution and test-cases for problem 3318

Author: 0xff-dev

leetcode/3301-3400/3318.Find-X-Sum-of-All-K-Long-Subarrays-I/README.md

@@ -1,28 +1,43 @@
 # [3318.Find X-Sum of All K-Long Subarrays I][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 `nums` of `n` integers and two integers `k` and `x`.
+
+The **x-sum** of an array is calculated by the following procedure:
+
+- Count the occurrences of all elements in the array.
+- Keep only the occurrences of the top `x` most frequent elements. If two elements have the same number of occurrences, the element with the **bigger** value is considered more frequent.
+- Calculate the sum of the resulting array.
+
+**Note** that if an array has less than `x` distinct elements, its **x-sum** is the sum of the array.
+
+Return an integer array `answer` of length `n - k + 1` where `answer[i]` is the **x-sum** of the subarray `nums[i..i + k - 1]`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
-```
+Input: nums = [1,1,2,2,3,4,2,3], k = 6, x = 2
 
-## 题意
-> ...
+Output: [6,10,12]
 
-## 题解
+Explanation:
 
-### 思路1
-> ...
-Find X-Sum of All K-Long Subarrays I
-```go
+For subarray [1, 1, 2, 2, 3, 4], only elements 1 and 2 will be kept in the resulting array. Hence, answer[0] = 1 + 1 + 2 + 2.
+For subarray [1, 2, 2, 3, 4, 2], only elements 2 and 4 will be kept in the resulting array. Hence, answer[1] = 2 + 2 + 2 + 4. Note that 4 is kept in the array since it is bigger than 3 and 1 which occur the same number of times.
+For subarray [2, 2, 3, 4, 2, 3], only elements 2 and 3 are kept in the resulting array. Hence, answer[2] = 2 + 2 + 2 + 3 + 3.
 ```
 
+**Example 2:**
+
+```
+Input: nums = [3,8,7,8,7,5], k = 2, x = 2
+
+Output: [11,15,15,15,12]
+
+Explanation:
+
+Since k == x, answer[i] is equal to the sum of the subarray nums[i..i + k - 1].
+```
 
 ## 结语
 

leetcode/3301-3400/3318.Find-X-Sum-of-All-K-Long-Subarrays-I/Solution.go

@@ -1,5 +1,57 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import (
+	"sort"
+)
+
+type ElementInfo struct {
+	Value int
+	Freq  int
+}
+
+func Solution(nums []int, k int, x int) []int {
+	n := len(nums)
+	if k == 0 || n < k {
+		return []int{}
+	}
+
+	answer := make([]int, n-k+1)
+
+	for i := 0; i <= n-k; i++ {
+		freqMap := make(map[int]int)
+		for j := i; j < i+k; j++ {
+			freqMap[nums[j]]++
+		}
+
+		var elements []ElementInfo
+		for val, freq := range freqMap {
+			elements = append(elements, ElementInfo{
+				Value: val,
+				Freq:  freq,
+			})
+		}
+
+		sort.Slice(elements, func(a, b int) bool {
+			if elements[a].Freq != elements[b].Freq {
+				return elements[a].Freq > elements[b].Freq
+			}
+			return elements[a].Value > elements[b].Value
+		})
+
+		currentXSum := 0
+
+		limit := x
+		if len(elements) < x {
+			limit = len(elements)
+		}
+
+		for idx := 0; idx < limit; idx++ {
+			element := elements[idx]
+			currentXSum += element.Value * element.Freq
+		}
+
+		answer[i] = currentXSum
+	}
+
+	return answer
 }

leetcode/3301-3400/3318.Find-X-Sum-of-All-K-Long-Subarrays-I/Solution_test.go

@@ -10,30 +10,30 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []int
+		k, x   int
+		expect []int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 1, 2, 2, 3, 4, 2, 3}, 6, 2, []int{6, 10, 12}},
+		{"TestCase2", []int{3, 8, 7, 8, 7, 5}, 2, 2, []int{11, 15, 15, 15, 12}},
 	}
 
 	//	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.inputs, c.k, 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.inputs, c.k, 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() {
 }