Add solution #1192

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,175 LeetCode solutions in JavaScript
+# 1,176 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -924,6 +924,7 @@
 1189|[Maximum Number of Balloons](./solutions/1189-maximum-number-of-balloons.js)|Easy|
 1190|[Reverse Substrings Between Each Pair of Parentheses](./solutions/1190-reverse-substrings-between-each-pair-of-parentheses.js)|Medium|
 1191|[K-Concatenation Maximum Sum](./solutions/1191-k-concatenation-maximum-sum.js)|Medium|
+1192|[Critical Connections in a Network](./solutions/1192-critical-connections-in-a-network.js)|Hard|
 1200|[Minimum Absolute Difference](./solutions/1200-minimum-absolute-difference.js)|Easy|
 1206|[Design Skiplist](./solutions/1206-design-skiplist.js)|Hard|
 1207|[Unique Number of Occurrences](./solutions/1207-unique-number-of-occurrences.js)|Easy|

solutions/1192-critical-connections-in-a-network.js

@@ -0,0 +1,59 @@
+/**
+ * 1192. Critical Connections in a Network
+ * https://leetcode.com/problems/critical-connections-in-a-network/
+ * Difficulty: Hard
+ *
+ * There are n servers numbered from 0 to n - 1 connected by undirected server-to-server connections
+ * forming a network where connections[i] = [ai, bi] represents a connection between servers ai and
+ * bi. Any server can reach other servers directly or indirectly through the network.
+ *
+ * A critical connection is a connection that, if removed, will make some servers unable to reach
+ * some other server.
+ *
+ * Return all critical connections in the network in any order.
+ */
+
+/**
+ * @param {number} n
+ * @param {number[][]} connections
+ * @return {number[][]}
+ */
+var criticalConnections = function(n, connections) {
+  const graph = Array.from({ length: n }, () => []);
+  const discoveryTimes = new Array(n).fill(-1);
+  const lowestReachableTimes = new Array(n).fill(-1);
+  const criticalEdges = [];
+  let time = 0;
+
+  connections.forEach(([from, to]) => {
+    graph[from].push(to);
+    graph[to].push(from);
+  });
+
+  exploreNode(0, -1);
+
+  return criticalEdges;
+
+  function exploreNode(current, parent) {
+    discoveryTimes[current] = lowestReachableTimes[current] = time++;
+
+    for (const neighbor of graph[current]) {
+      if (neighbor === parent) continue;
+      if (discoveryTimes[neighbor] === -1) {
+        exploreNode(neighbor, current);
+        lowestReachableTimes[current] = Math.min(
+          lowestReachableTimes[current],
+          lowestReachableTimes[neighbor]
+        );
+        if (lowestReachableTimes[neighbor] > discoveryTimes[current]) {
+          criticalEdges.push([current, neighbor]);
+        }
+      } else {
+        lowestReachableTimes[current] = Math.min(
+          lowestReachableTimes[current],
+          discoveryTimes[neighbor]
+        );
+      }
+    }
+  }
+};