08.09: disjoint set(집합의 표현)

baekjoon/1717.js

@@ -0,0 +1,54 @@
+// 집합의 표현 : 분리 집합
+const input = require("fs")
+  .readFileSync(0, "utf-8")
+  .toString()
+  .trim()
+  .split("\n")
+  .map((v) => v.split(" ").map((v) => Number(v)));
+const [n, operationCount] = input.shift();
+const operation = input;
+const answer = [];
+const [OP_INTEGRATE, OP_CHECK] = [0, 1];
+const parents = new Array(n + 1).fill(0).map((_v, i) => i);
+
+function getParents(x) {
+  if (parents[x] === x) {
+    return x;
+  }
+
+  return (parents[x] = getParents(parents[x]));
+}
+
+function union(x, y) {
+  x = getParents(x);
+  y = getParents(y);
+
+  if (x > y) {
+    parents[x] = y;
+  } else {
+    parents[y] = x;
+  }
+}
+
+function isSameParent(x, y) {
+  return getParents(x) === getParents(y);
+}
+
+for (const [op, a, b] of operation) {
+  if (op === OP_CHECK) {
+    answer.push(isSameParent(a, b) ? "YES" : "NO");
+  }
+  if (op === OP_INTEGRATE) {
+    union(a, b);
+  }
+}
+
+console.log(answer.join("\n"));
+
+// 0, 1, 2, 3, 4, 5, 6, 7
+// {1, 3}, 2, 4, 5, 6, 7
+// {1, 3}, 2, 4, 5, {6, 7}
+// {1, 3, 6, 7}, 2, 4, 5
+// {1, 3, 6, 7}, {2, 4}, 5
+
+// require("fs").readFileSync("/dev/stdin") 대신 require("fs").readFileSync(0, "utf-8")를 사용해야 권한 문제가 발생하지 않음