number of connected components in an undirected graph solution

Author: hyer0705

number-of-connected-components-in-an-undirected-graph/hyer0705.ts

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+export class Solution {
+  /**
+   * @param n: the number of vertices
+   * @param edges: the edges of undirected graph
+   * @return: the number of connected components
+   */
+  countComponents(n: number, edges: number[][]): number {
+    const parent = Array.from({ length: n }, (_, i) => i);
+    let components = n;
+
+    const find = (i: number): number => {
+      if (parent[i] === i) {
+        return i;
+      }
+
+      parent[i] = find(parent[i]);
+      return parent[i];
+    };
+
+    const union = (a: number, b: number): void => {
+      const rootA = find(a);
+      const rootB = find(b);
+
+      if (rootA !== rootB) {
+        parent[rootA] = rootB;
+        components--;
+      }
+    };
+
+    for (const [a, b] of edges) {
+      union(a, b);
+    }
+
+    return components;
+  }
+}