Add solution #547

Author: JoshCrozier

Diff for: README.md

@@ -210,6 +210,7 @@
 520|[Detect Capital](./0520-detect-capital.js)|Easy|
 541|[Reverse String II](./0541-reverse-string-ii.js)|Easy|
 542|[01 Matrix](./0542-01-matrix.js)|Medium|
+547|[Number of Provinces](./0547-number-of-provinces.js)|Medium|
 551|[Student Attendance Record I](./0551-student-attendance-record-i.js)|Easy|
 557|[Reverse Words in a String III](./0557-reverse-words-in-a-string-iii.js)|Easy|
 563|[Binary Tree Tilt](./0563-binary-tree-tilt.js)|Easy|

Diff for: solutions/0547-number-of-provinces.js

@@ -0,0 +1,44 @@
+/**
+ * 547. Number of Provinces
+ * https://leetcode.com/problems/number-of-provinces/
+ * Difficulty: Medium
+ *
+ * There are n cities. Some of them are connected, while some are not. If city a is connected
+ * directly with city b, and city b is connected directly with city c, then city a is connected
+ * indirectly with city c.
+ *
+ * A province is a group of directly or indirectly connected cities and no other cities outside
+ * of the group.
+ *
+ * You are given an n x n matrix isConnected where isConnected[i][j] = 1 if the ith city and the
+ * jth city are directly connected, and isConnected[i][j] = 0 otherwise.
+
+Return the total number of provinces.
+ */
+
+/**
+ * @param {number[][]} isConnected
+ * @return {number}
+ */
+var findCircleNum = function(isConnected) {
+  const seen = new Array(isConnected.length).fill(0);
+  let result = 0;
+
+  function dfs(node) {
+    seen[node] = 1;
+    for (let i = 0; i < isConnected.length; i++) {
+      if (isConnected[node][i] === 1 && !seen[i]) {
+        dfs(i);
+      }
+    }
+  }
+
+  for (let i = 0; i < isConnected.length; i++) {
+    if (!seen[i]) {
+      result++;
+      dfs(i);
+    }
+  }
+
+  return result;
+};