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

Author: kimyou1102

Diff for: 3주차/박종운/실버1__미로_탐색.js

@@ -0,0 +1,69 @@
+const local_input = `
+4 6
+101111
+101010
+101011
+111011
+`;
+
+const input = process.execArgv.includes("--stack-size=65536")
+  ? require("fs").readFileSync("dev/stdin").toString()
+  : local_input;
+
+const lines = input.trim().split('\n');
+
+const [N, M] = lines[0].split(' ').map(Number);
+const map = lines.slice(1).map(el => el.split(''));
+const history = new Set(['0,0']);
+const tree = [
+  new Set(['0,0']),
+]
+
+for(let i=1; i<=N*M; i++) {
+  const lastSet = tree[tree.length - 1];
+  const newSet = new Set();
+  lastSet.forEach(str => {
+    const [y, x] = str.split(',').map(Number);
+
+    if(y-1 >= 0 && y-1 < N && map[y-1][x] === '1') { // 위
+      const str = `${y-1},${x}`;
+
+      if(!history.has(str)) {
+        newSet.add(str) 
+        history.add(str) 
+      }
+    }
+    if(y+1 >= 0 && y+1 < N && map[y+1][x] === '1') { // 아래
+      const str = `${y+1},${x}`;
+
+      if(!history.has(str)) {
+        newSet.add(str) 
+        history.add(str) 
+      }
+    }
+    if(x-1 >= 0 && x-1 < M && map[y][x-1] === '1') { // 왼쪽
+      const str = `${y},${x-1}`;
+
+      if(!history.has(str)) {
+        newSet.add(str) 
+        history.add(str) 
+      }
+    }
+    if(x+1 >= 0 && x+1 < M && map[y][x+1] === '1') { // 오른쪽
+      const str = `${y},${x+1}`;
+
+      if(!history.has(str)) {
+        newSet.add(str) 
+        history.add(str) 
+      }
+    }
+
+  })
+
+  if(newSet.has(`${N-1},${M-1}`)) {  
+    console.log(tree.length + 1)
+    return null
+  }
+
+  tree.push(newSet);
+}

Diff for: 3주차/이진아/레벨3__가장먼노드.js

@@ -0,0 +1,28 @@
+function solution (n, edge) {
+    //1. 연결리스트 생성
+    const connects = new Array(n).fill().map(_ => []);
+
+    //2. 양방향으로 연결리스트를 채워줌
+    //edge 배열의 각 요소에 대해 반복
+    for(const e of edge) {
+      connects[e[0]-1].push(e[1]-1);
+      connects[e[1]-1].push(e[0]-1);
+    }
+    
+    const visited = [1];
+    const queue = [0];
+    while(queue.length) {
+      const cur = queue.shift();
+      
+      for(const next of connects[cur]) {
+        if(!visited[next]) {
+          visited[next] = visited[cur] + 1;
+          queue.push(next);
+        }
+      }
+    }
+    //visited 배열에서 최대 거리를 구한다
+    const max = Math.max(...visited);
+    //최대 거리와 같은 값을 가지는 요소들의 개수를 세어 반환
+    return visited.filter(el => el === max).length;
+  }

Diff for: 3주차/이진아/실버1__미로탐색.js

@@ -0,0 +1,35 @@
+let input = require('fs').readFileSync('dev/stdin').toString().trim().split('\n');
+
+const [n, m] = input.shift().split(" ");
+let graph = input.map(arr => arr.split("").map(x => +x));
+
+const BFS = (n, m, arr) => {
+    const dx = [-1, 0, 1, 0];
+    const dy = [0, 1, 0, -1];
+    
+    let queue = [];
+    queue.push({x: 0, y: 0}); 
+
+    while (queue.length) {
+        const target = queue.shift();
+        for (let i = 0; i < 4; i++) {
+            const nextX = target.x + dx[i];
+            const nextY = target.y + dy[i];
+            
+            if (nextX < 0 || nextX >= n || nextY < 0 || nextY >= m) {
+                continue;
+            }
+            
+            if (arr[nextX][nextY] !== 1) {
+                continue;
+            }
+            
+            arr[nextX][nextY] = arr[target.x][target.y] + 1;
+            queue.push({x: nextX, y: nextY});
+        }
+    }
+    return arr[n-1][m-1];
+}
+
+const answer = BFS(n, m, graph)
+console.log(answer)

Diff for: 4주차/박종운/골드4__사회망_서비스.js

@@ -0,0 +1,42 @@
+const readline = require('readline');
+
+const rl = readline.createInterface({
+  input: process.execArgv.includes("--stack-size=65536") ? 
+    process.stdin : require('fs').createReadStream(__dirname + '/input.txt'),
+  output: process.stdout
+});
+
+let N;
+let graph;
+let dp;
+let visited;
+
+function dfs(cur) {
+  visited[cur] = true;
+
+  for (const child of graph[cur]) {
+    if (!visited[child]) {
+      dfs(child);
+      dp[cur][0] += dp[child][1];
+      dp[cur][1] += Math.min(...dp[child]);
+    }
+  }
+}
+
+rl.question('', input => {
+  N = parseInt(input);
+  graph = Array.from({ length: N + 1 }, () => []);
+  dp = Array.from({ length: N + 1 }, () => [0, 1]);
+  visited = Array(N + 1).fill(false);
+
+  rl.on('line', line => {
+    const [u, v] = line.split(' ').map(Number);
+    graph[u].push(v);
+    graph[v].push(u);
+  }).on('close', () => {
+    dfs(1);
+    console.log(Math.min(...dp[1]));
+
+    process.exit();
+  });
+});

Diff for: 4주차/박종운/레벨3__길_찾기_게임.js

@@ -0,0 +1,28 @@
+function solution(nodeinfo) {
+    const nodes = nodeinfo.map((el, i) => [i+1, ...el]);
+    
+    const sorted = nodes.sort((a, b) => b[2] === a[2] ? a[1] - b[1] : b[2] - a[2]);
+
+    const preorder = [];
+    const postorder = [];
+
+    function traverse(arr) {
+        if(!arr.length) return;
+        
+        const current = arr[0];
+        
+        preorder.push(current[0]);
+        
+        const newLeft = arr.filter(el => el[2] < current[2] && el[1] < current[1]);
+        const newRight = arr.filter(el => el[2] < current[2] && el[1] > current[1] );
+        
+        traverse(newLeft);
+        traverse(newRight);
+        
+        postorder.push(current[0]);
+    }
+
+    traverse(sorted);
+    
+    return [preorder, postorder];
+}

Diff for: 4주차/박종운/실버2__트리의_부모_찾기.js

@@ -0,0 +1,45 @@
+const local_input = `
+7
+1 6
+6 3
+3 5
+4 1
+2 4
+4 7
+`;
+
+const input = process.execArgv.includes("--stack-size=65536")
+  ? require("fs").readFileSync("dev/stdin").toString()
+  : local_input;
+
+const lines = input.trim().split('\n');
+
+const N = Number(lines[0]);
+const edges = lines.slice(1).map(el => el.split(' ').map(Number));
+
+const graph = {};
+
+edges.forEach(el => {
+  if(!graph[el[0]]) graph[el[0]] = [];
+  if(!graph[el[1]]) graph[el[1]] = [];
+  graph[el[0]].push(el[1])
+  graph[el[1]].push(el[0])
+})
+
+const queue = [1];
+const visited = new Set([1]);
+const parentNodes = [];
+
+while(queue.length) {
+  const currentNode = queue.shift();
+  const childNodes = graph[currentNode].filter(childNode => !visited.has(childNode));
+
+  childNodes.forEach(childNode => {
+    parentNodes[childNode] = currentNode;
+    queue.push(childNode);
+  })
+  
+  visited.add(currentNode);
+}
+
+console.log(parentNodes.slice(2).join('\n'))

Diff for: 4주차/채수혁/골드4__사회망_서비스(SNS).js

@@ -0,0 +1,49 @@
+const local_input = `
+8
+1 2
+1 3
+1 4
+2 5
+2 6
+4 7
+4 8
+`;
+
+const input = process.execArgv.includes("--stack-size=65536")
+  ? require("fs").readFileSync("dev/stdin").toString()
+  : local_input;
+const inputs = input
+  .trim()
+  .split("\n")
+  .slice(1)
+  .map((v) => v.split(" ").map((v2) => Number(v2)));
+
+const n = Number(input.trim().split("\n")[0]);
+const dp = Array.from({ length: n + 1 }, () =>
+  Array.from({ length: 2 }, () => 0)
+);
+
+const map = {};
+const visited = Array.from({ length: n + 1 }, () => false);
+inputs.forEach((v) => {
+  if (map[v[0]]) map[v[0]].push(v[1]);
+  else map[v[0]] = [v[1]];
+  if (map[v[1]]) map[v[1]].push(v[0]);
+  else map[v[1]] = [v[0]];
+});
+
+const dfs = (cur) => {
+  visited[cur] = true;
+  dp[cur][0] = 0;
+  dp[cur][1] = 1;
+
+  for (const node of map[cur]) {
+    if (visited[node]) continue;
+    dfs(node);
+    dp[cur][0] += dp[node][1];
+    dp[cur][1] += Math.min(dp[node][0], dp[node][1]);
+  }
+};
+
+dfs(1);
+console.log(Math.min(dp[1][0], dp[1][1]));

Diff for: 4주차/채수혁/실버2__트리의_부모_찾기.js

@@ -0,0 +1,42 @@
+const local_input = `
+7
+1 6
+6 3
+3 5
+4 1
+2 4
+4 7
+`;
+
+const input = process.execArgv.includes("--stack-size=65536")
+  ? require("fs").readFileSync("dev/stdin").toString()
+  : local_input;
+
+const inputs = input.trim().split("\n");
+let cnt = 0;
+const n = Number(inputs[0]);
+const arr = inputs.slice(1).map((v) => v.split(" ").map((v2) => Number(v2)));
+const map = {};
+arr.forEach((v) => {
+  if (map[v[0]]) map[v[0]].push(v[1]);
+  else map[v[0]] = [v[1]];
+  if (map[v[1]]) map[v[1]].push(v[0]);
+  else map[v[1]] = [v[0]];
+});
+const parents = Array.from({ length: n + 1 }, () => 0);
+const visited = Array.from({ length: n + 1 }, () => false);
+
+const que = [[1, map[1]]];
+
+while (que.length > 0) {
+  const [cur, nodeArr] = que.shift();
+
+  visited[cur] = true;
+
+  for (const node of nodeArr) {
+    if (visited[node]) continue;
+    parents[node] = cur;
+    que.push([node, map[node]]);
+  }
+}
+console.log(parents.slice(2).reduce((a, v) => a + v + "\n", ""));