Merge pull request #794 from 0xff-dev/2092

Add solution and test-cases for problem 2092

leetcode/2001-2100/2092.Find-All-People-With-Secret/README.md

@@ -1,28 +1,51 @@
 # [2092.Find All People With Secret][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 `n` indicating there are `n` people numbered from `0` to `n - 1`. You are also given a **0-indexed** 2D integer array `meetings` where `meetings[i] = [xi, yi, timei]` indicates that person `xi` and person `yi` have a meeting at `timei`. A person may attend **multiple meetings** at the same time. Finally, you are given an integer `firstPerson`.
+
+Person `0` has a **secret** and initially shares the secret with a person `firstPerson` at time `0`. This secret is then shared every time a meeting takes place with a person that has the secret. More formally, for every meeting, if a person `xi` has the secret at `timei`, then they will share the secret with person `yi`, and vice versa.
+
+The secrets are shared **instantaneously**. That is, a person may receive the secret and share it with people in other meetings within the same time frame.
+
+Return a list of all the people that have the secret after all the meetings have taken place. You may return the answer in **any order**.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: n = 6, meetings = [[1,2,5],[2,3,8],[1,5,10]], firstPerson = 1
+Output: [0,1,2,3,5]
+Explanation:
+At time 0, person 0 shares the secret with person 1.
+At time 5, person 1 shares the secret with person 2.
+At time 8, person 2 shares the secret with person 3.
+At time 10, person 1 shares the secret with person 5.​​​​
+Thus, people 0, 1, 2, 3, and 5 know the secret after all the meetings.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Find All People With Secret
-```go
 ```
+Input: n = 4, meetings = [[3,1,3],[1,2,2],[0,3,3]], firstPerson = 3
+Output: [0,1,3]
+Explanation:
+At time 0, person 0 shares the secret with person 3.
+At time 2, neither person 1 nor person 2 know the secret.
+At time 3, person 3 shares the secret with person 0 and person 1.
+Thus, people 0, 1, and 3 know the secret after all the meetings.
+```
+
+**Example 3:**
 
+```
+Input: n = 5, meetings = [[3,4,2],[1,2,1],[2,3,1]], firstPerson = 1
+Output: [0,1,2,3,4]
+Explanation:
+At time 0, person 0 shares the secret with person 1.
+At time 1, person 1 shares the secret with person 2, and person 2 shares the secret with person 3.
+Note that person 2 can share the secret at the same time as receiving it.
+At time 2, person 3 shares the secret with person 4.
+Thus, people 0, 1, 2, 3, and 4 know the secret after all the meetings.
+```
 
 ## 结语
 

leetcode/2001-2100/2092.Find-All-People-With-Secret/Solution.go

@@ -1,5 +1,79 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "sort"
+
+type unionFinc2092 struct {
+	father []int
+}
+
+func (u *unionFinc2092) find(x int) int {
+	if u.father[x] != x {
+		u.father[x] = u.find(u.father[x])
+	}
+	return u.father[x]
+}
+
+func (u *unionFinc2092) union(x, y int) {
+	fx := u.find(x)
+	fy := u.find(y)
+	if fx < fy {
+		u.father[fy] = fx
+		return
+	}
+	u.father[fx] = fy
+}
+
+func Solution(n int, meetings [][]int, firstPerson int) []int {
+	sort.Slice(meetings, func(i, j int) bool {
+		return meetings[i][2] < meetings[j][2]
+	})
+
+	u := unionFinc2092{father: make([]int, n)}
+	for i := 0; i < n; i++ {
+		u.father[i] = i
+	}
+	u.father[firstPerson] = 0
+	startTime := -1
+	for cur, meet := range meetings {
+		if meet[2] == startTime {
+			u.union(meet[0], meet[1])
+			continue
+		}
+		for i := cur - 1; i >= 0; i-- {
+			if meetings[i][2] != startTime {
+				break
+			}
+			fx := u.find(meetings[i][0])
+			fy := u.find(meetings[i][1])
+			if fx == 0 || fy == 0 {
+				u.union(meetings[i][0], meetings[i][1])
+			} else {
+				u.father[meetings[i][0]] = meetings[i][0]
+				u.father[meetings[i][1]] = meetings[i][1]
+			}
+		}
+
+		startTime = meet[2]
+		u.union(meet[0], meet[1])
+	}
+	for i := len(meetings) - 1; i >= 0; i-- {
+		if meetings[i][2] != startTime {
+			break
+		}
+		fx := u.find(meetings[i][0])
+		fy := u.find(meetings[i][1])
+		if fx == 0 || fy == 0 {
+			u.union(meetings[i][0], meetings[i][1])
+		} else {
+			u.father[meetings[i][0]] = meetings[i][0]
+			u.father[meetings[i][1]] = meetings[i][1]
+		}
+	}
+	ans := make([]int, 0)
+	for i := 0; i < n; i++ {
+		if u.find(i) == 0 {
+			ans = append(ans, i)
+		}
+	}
+	return ans
 }

leetcode/2001-2100/2092.Find-All-People-With-Secret/Solution_test.go

@@ -9,31 +9,39 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name        string
+		n           int
+		meetings    [][]int
+		firstPerson int
+		expect      []int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", 6, [][]int{
+			{1, 2, 5}, {2, 3, 8}, {1, 5, 10},
+		}, 1, []int{0, 1, 2, 3, 5}},
+		{"TestCase2", 4, [][]int{
+			{3, 1, 3}, {1, 2, 2}, {0, 3, 3},
+		}, 3, []int{0, 1, 3}},
+		{"TestCase3", 5, [][]int{
+			{3, 4, 2}, {1, 2, 1}, {2, 3, 1},
+		}, 1, []int{0, 1, 2, 3, 4}},
 	}
 
 	//	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.n, c.meetings, c.firstPerson)
 			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.n, c.meetings, c.firstPerson)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }