Add solution and test-cases for problem 1352

Author: 0xff-dev

leetcode/1301-1400/1352.Product-of-the-Last-K-Numbers/README.md

@@ -1,28 +1,39 @@
 # [1352.Product of the Last K Numbers][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
+Design an algorithm that accepts a stream of integers and retrieves the product of the last `k` integers of the stream.
 
-**Example 1:**
+Implement the `ProductOfNumbers` class:
 
-```
-Input: a = "11", b = "1"
-Output: "100"
-```
+- `ProductOfNumbers()` Initializes the object with an empty stream.
+- `void add(int num)` Appends the integer `num` to the stream.
+- `int getProduct(int k)` Returns the product of the last `k` numbers in the current list. You can assume that always the current list has at least `k` numbers.
 
-## 题意
-> ...
+The test cases are generated so that, at any time, the product of any contiguous sequence of numbers will fit into a single 32-bit integer without overflowing.
 
-## 题解
+**Example 1:**
 
-### 思路1
-> ...
-Product of the Last K Numbers
-```go
 ```
-
+Input
+["ProductOfNumbers","add","add","add","add","add","getProduct","getProduct","getProduct","add","getProduct"]
+[[],[3],[0],[2],[5],[4],[2],[3],[4],[8],[2]]
+
+Output
+[null,null,null,null,null,null,20,40,0,null,32]
+
+Explanation
+ProductOfNumbers productOfNumbers = new ProductOfNumbers();
+productOfNumbers.add(3);        // [3]
+productOfNumbers.add(0);        // [3,0]
+productOfNumbers.add(2);        // [3,0,2]
+productOfNumbers.add(5);        // [3,0,2,5]
+productOfNumbers.add(4);        // [3,0,2,5,4]
+productOfNumbers.getProduct(2); // return 20. The product of the last 2 numbers is 5 * 4 = 20
+productOfNumbers.getProduct(3); // return 40. The product of the last 3 numbers is 2 * 5 * 4 = 40
+productOfNumbers.getProduct(4); // return 0. The product of the last 4 numbers is 0 * 2 * 5 * 4 = 0
+productOfNumbers.add(8);        // [3,0,2,5,4,8]
+productOfNumbers.getProduct(2); // return 32. The product of the last 2 numbers is 4 * 8 = 32
+```
 
 ## 结语
 

leetcode/1301-1400/1352.Product-of-the-Last-K-Numbers/Solution.go

@@ -1,5 +1,56 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+type ProductOfNumbers struct {
+	data  []int
+	zeros map[int]struct{}
+}
+
+func Constructor() ProductOfNumbers {
+	return ProductOfNumbers{data: make([]int, 0), zeros: map[int]struct{}{}}
+}
+
+func (this *ProductOfNumbers) Add(num int) {
+	if num == 0 {
+		this.data = append(this.data, num)
+		this.zeros[len(this.data)-1] = struct{}{}
+		return
+	}
+	if len(this.data) != 0 {
+		if last := this.data[len(this.data)-1]; last != 0 {
+			num *= last
+		}
+	}
+	this.data = append(this.data, num)
+}
+
+func (this *ProductOfNumbers) GetProduct(k int) int {
+	end := len(this.data) - 1
+	start := end - k
+	for i := range this.zeros {
+		if i > start && i <= end {
+			return 0
+		}
+	}
+	if start < 0 || this.data[start] == 0 {
+		return this.data[end]
+	}
+	return this.data[end] / this.data[start]
+}
+
+type op struct {
+	name string
+	v    int
+}
+
+func Solution(opts []op) []int {
+	c := Constructor()
+	ans := make([]int, 0)
+	for _, o := range opts {
+		if o.name == "a" {
+			c.Add(o.v)
+			continue
+		}
+		ans = append(ans, c.GetProduct(o.v))
+	}
+	return ans
 }

leetcode/1301-1400/1352.Product-of-the-Last-K-Numbers/Solution_test.go

@@ -10,12 +10,17 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []op
+		expect []int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []op{
+			{"a", 3}, {"a", 0},
+			{"a", 2},
+			{"a", 5},
+			{"a", 4},
+			{"", 2}, {"", 3},
+			{"", 4}, {"a", 8}, {"", 2},
+		}, []int{20, 40, 0, 32}},
 	}
 
 	//	开始测试
@@ -30,10 +35,10 @@ 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() {
 }