Merge pull request #1055 from 0xff-dev/2054

Add solution and test-cases for problem 2054

Author: 6boris

leetcode/2001-2100/2054.Two-Best-Non-Overlapping-Events/1.png

@@ -1,28 +1,41 @@
 # [2054.Two Best Non-Overlapping Events][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 a **0-indexed** 2D integer array of `events` where `events[i] = [startTimei, endTimei, valuei]`. The `ith` event starts at `startTimei` and ends at `endTimei`, and if you attend this event, you will receive a value of `valuei`. You can choose **at most two non-overlapping** events to attend such that the sum of their values is **maximized**.
+
+Return this **maximum** sum.
+
+Note that the start time and end time is **inclusive**: that is, you cannot attend two events where one of them starts and the other ends at the same time. More specifically, if you attend an event with end time `t`, the next event must start at or after `t + 1`.
 
-**Example 1:**
+**Example 1:**  
+
+![1](./1.png)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: events = [[1,3,2],[4,5,2],[2,4,3]]
+Output: 4
+Explanation: Choose the green events, 0 and 1 for a sum of 2 + 2 = 4.
 ```
 
-## 题意
-> ...
+**Example 2:**  
 
-## 题解
+![2](./2.png)
 
-### 思路1
-> ...
-Two Best Non-Overlapping Events
-```go
+```
+Input: events = [[1,3,2],[4,5,2],[1,5,5]]
+Output: 5
+Explanation: Choose event 2 for a sum of 5.
 ```
 
+**Example 3:**  
+
+![3](./3.png)
+
+```
+Input: events = [[1,5,3],[1,5,1],[6,6,5]]
+Output: 8
+Explanation: Choose events 0 and 2 for a sum of 3 + 5 = 8.
+```
 
 ## 结语
 

leetcode/2001-2100/2054.Two-Best-Non-Overlapping-Events/2.png

@@ -1,5 +1,58 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "sort"
+
+type SegmentTreeNode2054 struct {
+	Left, Right, Max      int
+	LeftChild, RightChild *SegmentTreeNode2054
+}
+
+func buildSegmentTree2054(nums [][]int, left, right int) *SegmentTreeNode2054 {
+	if left == right {
+		return &SegmentTreeNode2054{Left: left, Right: right, Max: nums[left][2]}
+	}
+
+	mid := (left + right) / 2
+	leftNode := buildSegmentTree2054(nums, left, mid)
+	rightNode := buildSegmentTree2054(nums, mid+1, right)
+	max := max(leftNode.Max, rightNode.Max)
+
+	return &SegmentTreeNode2054{Left: left, Right: right, Max: max, LeftChild: leftNode, RightChild: rightNode}
+}
+
+func queryMax2054(root *SegmentTreeNode2054, left, right int) int {
+	if root.Left >= left && root.Right <= right {
+		return root.Max
+	}
+
+	if root.Right < left || root.Left > right {
+		return -1
+	}
+
+	return max(queryMax2054(root.LeftChild, left, right), queryMax2054(root.RightChild, left, right))
+}
+
+func Solution(events [][]int) int {
+	sort.Slice(events, func(i, j int) bool {
+		a, b := events[i], events[j]
+		if a[0] == b[0] {
+			return a[1] < b[1]
+		}
+		return a[0] < b[0]
+	})
+	l := len(events)
+
+	tree := buildSegmentTree2054(events, 0, l-1)
+	ans := 0
+	for i, e := range events {
+		ans = max(ans, e[2])
+		idx := sort.Search(l-i-1, func(ii int) bool {
+			return events[i+1+ii][0] > e[1]
+		})
+		if idx == l-i-1 {
+			continue
+		}
+		ans = max(ans, e[2]+queryMax2054(tree, i+1+idx, l-1))
+	}
+	return ans
 }

leetcode/2001-2100/2054.Two-Best-Non-Overlapping-Events/3.png

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs [][]int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{{1, 3, 2}, {4, 5, 2}, {2, 4, 3}}, 4},
+		{"TestCase2", [][]int{{1, 3, 2}, {4, 5, 2}, {1, 5, 5}}, 5},
+		{"TestCase3", [][]int{{1, 5, 3}, {1, 5, 1}, {6, 6, 5}}, 8},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ 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() {
 }