feat: 2092. Find All People With Secret : 并查集

Author: upupming

leetcode/残酷刷题/2092. Find All People With Secret.ts

@@ -0,0 +1,35 @@
+function findAllPeople(n: number, meetings: number[][], firstPerson: number): number[] {
+  const fa = [...Array(n)].map((_, idx) => idx)
+  const get = (x: number): number => {
+    if (x === fa[x]) return x
+    return fa[x] = get(fa[x])
+  }
+  const merge = (x: number, y: number) => {
+    let fx = get(x); let fy = get(y)
+    // 优先让 0 做根节点
+    if (fx === 0) [fx, fy] = [fy, fx]
+    fa[fx] = fy
+  }
+  meetings.sort((a, b) => a[2] - b[2])
+  const m = meetings.length
+  merge(0, firstPerson)
+  for (let i = 0; i < m; ) {
+    let time = meetings[i][2]
+    let j = i
+    while (j < m && meetings[j][2] === time) {
+      merge(meetings[j][0], meetings[j][1])
+      j++
+    }
+    for (let k = i; k < j; k++) {
+      const [a, b] = meetings[k]
+      if (get(a) !== 0) fa[a] = a
+      if (get(b) !== 0) fa[b] = b
+    }
+    i = j
+  }
+  const ans = [0]
+  for (let i = 1; i < n; i++) {
+    if (get(i) === get(0)) ans.push(i)
+  }
+  return ans
+};

leetcode/残酷刷题/README.md

@@ -108,6 +108,8 @@
 ### 并查集
 
 - 1627. Graph Connectivity With Threshold
+- 2092. Find All People With Secret
+    - 并查集，宽搜都可以做
 
 #### 时光倒流