[BOJ] 2450 모양 정돈 (G2)

Author: ShipFriend0516

서정우/11주차/260311.js

@@ -0,0 +1,54 @@
+const fs = require("fs");
+const filePath = process.platform === "linux" ? "/dev/stdin" : "./서정우/input.txt";
+const input = fs
+  .readFileSync(filePath)
+  .toString()
+  .trim()
+  .split("\n")
+  .map((el) => el.trim());
+const N = parseInt(input[0]);
+const A = input[1].split(" ").map((x) => parseInt(x) - 1);
+
+const count = [0, 0, 0];
+for (const x of A) count[x]++;
+
+const perms = [
+  [0, 1, 2],
+  [0, 2, 1],
+  [1, 0, 2],
+  [1, 2, 0],
+  [2, 0, 1],
+  [2, 1, 0],
+];
+
+let answer = Infinity;
+
+for (const perm of perms) {
+  const B = [];
+  for (const x of perm) {
+    for (let i = 0; i < count[x]; i++) B.push(x);
+  }
+
+  const wrong = Array.from({ length: 3 }, () => [0, 0, 0]);
+  for (let i = 0; i < N; i++) {
+    if (A[i] !== B[i]) wrong[A[i]][B[i]]++;
+  }
+
+  let numChanges = 0;
+
+  for (let i = 0; i < 3; i++) {
+    for (let j = i + 1; j < 3; j++) {
+      const tmp = Math.min(wrong[i][j], wrong[j][i]);
+      numChanges += tmp;
+      wrong[i][j] -= tmp;
+      wrong[j][i] -= tmp;
+    }
+  }
+
+  numChanges += 2 * wrong[0][1];
+  numChanges += 2 * wrong[0][2];
+
+  answer = Math.min(answer, numChanges);
+}
+
+console.log(answer);

서정우/input.txt

@@ -1 +1,2 @@
-40 1 100
+8
+1 3 3 2 1 1 3 2