Merge branch 'main' of https://github.com/prgrms-web-devcourse/FEDC5_JavaScript_coding_test_study

Author: ienrum

Diff for: 4주차/김유경/레벨3__길_찾기_게임.js

@@ -0,0 +1,88 @@
+function solution(nodeinfo) {
+  let answer = [];
+
+  nodeinfo.map((x, i) => x.push(i + 1));
+  //y값이 큰 순으로 정렬, 아니면 x값이 작은 순으로 정렬
+  const sorted = nodeinfo.sort((a, b) => b[1] - a[1] || a[0] - b[0]);
+  const tree = new Tree();
+
+  for (let i = 0; i < sorted.length; i++) {
+    const [x, y, node] = sorted[i];
+    tree.insert(node, x);
+  }
+
+  tree.preOrder(tree.root);
+  tree.postOrder(tree.root);
+
+  answer.push(tree.pre);
+  answer.push(tree.post);
+
+  return answer;
+}
+
+class Node {
+  constructor(value, x) {
+    this.value = value;
+    this.left = null;
+    this.right = null;
+    this.x = x;
+  }
+}
+
+class Tree {
+  constructor() {
+    this.root = null;
+    this.pre = [];
+    this.post = [];
+  }
+
+  insert(value, x) {
+    if (this.root === null) {
+      this.root = new Node(value, x);
+      return;
+    }
+    const queue = [];
+    queue.push(this.root);
+
+    while (queue.length > 0) {
+      const currentNode = queue.shift();
+      const newNode = new Node(value, x);
+
+      // 부모보다 현재의 새로은 node값의 x가 더 작다면 왼쪽으로
+      if (currentNode.x > newNode.x) {
+        if (currentNode.left === null) {
+          currentNode.left = newNode;
+          break;
+        } else {
+          queue.push(currentNode.left);
+        }
+        // 아니라면 오른쪽으로
+      } else {
+        if (currentNode.right === null) {
+          currentNode.right = newNode;
+          break;
+        } else {
+          queue.push(currentNode.right);
+        }
+      }
+    }
+  }
+
+  preOrder(node) {
+    if (!node) {
+      return;
+    }
+    this.pre.push(node.value);
+    this.preOrder(node.left);
+    this.preOrder(node.right);
+  }
+
+  postOrder(node) {
+    if (!node) {
+      return;
+    }
+    this.postOrder(node.left);
+    this.postOrder(node.right);
+    this.post.push(node.value);
+  }
+}

Diff for: 4주차/김유경/실버2__트리의_부모_찾기_11725.js

@@ -0,0 +1,37 @@
+const fs = require("fs");
+const filePath =
+  process.platform === "linux" ? "/dev/stdin" : `${__dirname}/input.txt`;
+let input = fs.readFileSync(filePath).toString().trim().split("\n");
+
+const n = Number(input.shift());
+const arr = input.map((x) =>
+  x
+    .trim()
+    .split(" ")
+    .map((x) => +x)
+);
+
+const graph = Array.from(Array(n + 1), () => []);
+const visited = Array(n + 1).fill(false);
+const parent = Array(n + 1).fill(0);
+
+arr.forEach(([v, u]) => {
+  graph[u].push(v);
+  graph[v].push(u);
+});
+
+dfs(1);
+
+function dfs(i) {
+  if (!visited[i]) {
+    visited[i] = true;
+    graph[i].forEach((e) => {
+      if (!visited[e]) {
+        parent[e] = i;
+        dfs(e);
+      }
+    });
+  }
+}
+
+console.log(parent.slice(2).join("\n"));