10.04 : bfs, least distance(미로 탐색)

baekjoon/2178.js

@@ -0,0 +1,59 @@
+// 미로 탐색 : 그래프 탐색, 너비 우선 탐색
+const Queue = require("./queue");
+const input = require("fs")
+  .readFileSync("/dev/stdin")
+  .toString()
+  .trim()
+  .split("\n");
+const [n, m] = input
+  .shift()
+  .split(" ")
+  .map((v) => parseInt(v, 10));
+const map = input.map((v) => v.split("").map((v) => parseInt(v, 10)));
+const visited = map.map((v) => v.map((v) => false));
+const dir = [
+  [-1, 0],
+  [0, 1],
+  [1, 0],
+  [0, -1],
+];
+const q1 = new Queue();
+const q2 = new Queue();
+let isFirst = true;
+let i = 0,
+  j = 0;
+let cnt = 1;
+let flag = false;
+
+q1.push([i, j]);
+visited[i][j] = true;
+
+while (!(q1.size === 0 && q2.size === 0)) {
+  while (isFirst ? q1.size !== 0 : q2.size !== 0) {
+    const top = isFirst ? q1.head.value : q2.head.value;
+    isFirst ? q1.pop() : q2.pop();
+    for (let i = 0; i < 4; i++) {
+      const next = [top[0] + dir[i][0], top[1] + dir[i][1]];
+      if (
+        next[0] < 0 ||
+        next[0] >= n ||
+        next[1] < 0 ||
+        next[1] >= m ||
+        map[next[0]][next[1]] === 0 ||
+        visited[next[0]][next[1]] === true
+      )
+        continue;
+      isFirst ? q2.push(next) : q1.push(next);
+      visited[next[0]][next[1]] = true;
+      if (next[0] === n - 1 && next[1] === m - 1) {
+        flag = true;
+        break;
+      }
+    }
+  }
+  cnt++;
+  isFirst = !isFirst;
+  if (flag) break;
+}
+
+console.log(cnt);

baekjoon/queue.js

@@ -51,3 +51,5 @@ class Queue {
 
   front = () => this.head.value;
 }
+
+module.exports = Queue;