1주차 BOJ 문제풀이

naekang/boj1158.java

@@ -0,0 +1,39 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.StringTokenizer;
+
+public class boj1158 {
+  public static void main(String[] args) throws IOException {
+    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    StringTokenizer st = new StringTokenizer(br.readLine());
+    StringBuilder sb = new StringBuilder();
+
+    int N = Integer.parseInt(st.nextToken());
+    int K = Integer.parseInt(st.nextToken());
+
+    Queue<Integer> queue = new LinkedList<>();
+
+    // 1부터 N까지의 숫자를 queue에 삽입
+    for (int i = 1; i <= N; i++) {
+      queue.add(i);
+    }
+
+    sb.append("<");
+
+    // queue의 크기가 1이될때까지 반복
+    while (queue.size() != 1) {
+      // K - 1번째까지 queue 앞에서 꺼내서 뒤로 넣기
+      for (int i = 0; i < K - 1; i++) {
+        queue.add(queue.poll());
+      }
+      sb.append(queue.poll()).append(", ");
+    }
+    // 큐의 마지막에 남은 숫자를 꺼낸다
+    sb.append(queue.poll()).append(">");
+
+    System.out.println(sb);
+  }
+}

naekang/boj17413.java

@@ -0,0 +1,47 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Stack;
+
+public class boj17413 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+
+        String S = br.readLine();
+
+        Stack<Character> stack = new Stack<>();
+        boolean checkIsIn = false;
+
+        for (int i = 0; i < S.length(); i++) {
+            if (S.charAt(i) == '<') {
+                checkIsIn = true;
+
+                while (!stack.isEmpty()) {
+                    sb.append(stack.pop());
+                }
+                sb.append(S.charAt(i));
+            } else if (S.charAt(i) == '>') {
+                checkIsIn = false;
+                sb.append(S.charAt(i));
+            } else if (checkIsIn) {
+                sb.append(S.charAt(i));
+            } else if (!checkIsIn) {
+                if (S.charAt(i) == ' ') {
+                    while (!stack.isEmpty()) {
+                        sb.append(stack.pop());
+                    }
+                    sb.append(S.charAt(i));
+                } else {
+                    stack.push(S.charAt(i));
+                }
+            }
+        }
+
+        while (!stack.isEmpty()) {
+            sb.append(stack.pop());
+        }
+
+        System.out.println(sb);
+    }
+}

naekang/boj9012.java

@@ -0,0 +1,42 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Stack;
+
+public class boj9012 {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+
+        int T = Integer.parseInt(br.readLine());
+
+        while (T-- > 0) {
+            Stack<Character> stack = new Stack<>();
+            String str = br.readLine();
+            boolean flag = false;
+
+            for (int i = 0; i < str.length(); i++) {
+                char ch = str.charAt(i);
+
+                if (ch == '(') {
+                    stack.push(ch);
+                } else if (ch == ')') {
+                    if (!stack.isEmpty()) {
+                        stack.pop();
+                    } else {
+                        flag = true;
+                        break;
+                    }
+                }
+            }
+            if (stack.isEmpty() && !flag) {
+                sb.append("YES").append("\n");
+            } else {
+                sb.append("NO").append("\n");
+            }
+        }
+
+        System.out.println(sb);
+    }
+}