[BOJ] 21938 영상처리 (S2)

Author: ShipFriend0516

서정우/12주차/260316.js

@@ -0,0 +1,57 @@
+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, M] = input[0].split(" ").map(Number);
+const displayRGB = input.slice(1, N + 1).map((el) => el.split(" ").map(Number));
+const threshold = Number(input[N + 1]);
+
+const display = Array.from({ length: N }, () => new Array(M).fill(0));
+
+for (let i = 0; i < displayRGB.length; i++) {
+  const row = displayRGB[i];
+  for (let j = 0; j < row.length / 3; j++) {
+    display[i][j] =
+      row.slice(j * 3, j * 3 + 3).reduce((acc, cur) => acc + cur, 0) / 3 >= threshold ? 255 : 0;
+  }
+}
+
+const bfs = (startX, startY) => {
+  const queue = [[startX, startY]];
+  const directions = [
+    [1, 0],
+    [-1, 0],
+    [0, 1],
+    [0, -1],
+  ];
+
+  while (queue.length) {
+    const [x, y] = queue.shift();
+    for (const [dx, dy] of directions) {
+      const newX = x + dx;
+      const newY = y + dy;
+      if (newX >= 0 && newX < N && newY >= 0 && newY < M && display[newX][newY] === 255) {
+        display[newX][newY] = 0;
+        queue.push([newX, newY]);
+      }
+    }
+  }
+};
+
+let count = 0;
+for (let i = 0; i < N; i++) {
+  for (let j = 0; j < M; j++) {
+    if (display[i][j] === 255) {
+      count++;
+      display[i][j] = 0;
+      bfs(i, j);
+    }
+  }
+}
+
+console.log(count);

서정우/input.txt

@@ -1,2 +1,5 @@
-6 10 12
-11 10 17 5 23 28
+3 3
+255 255 255 100 100 100 255 255 255
+100 100 100 255 255 255 100 100 100
+255 255 255 100 100 100 255 255 255
+101