Add: algorithms of baekjoon

Author: ImSejin

src/main/java/io/github/imsejin/study/baekjoon/silver/P2164.java

@@ -0,0 +1,43 @@
+package io.github.imsejin.study.baekjoon.silver;
+
+import io.github.imsejin.study.meta.Problem;
+import io.github.imsejin.study.meta.Tag;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.ArrayDeque;
+import java.util.Objects;
+import java.util.Queue;
+
+@Problem(tags = {
+        Tag.DATA_STRUCTURE,
+})
+public class P2164 {
+
+    public static void main(String[] args) throws Exception {
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
+            int count = Integer.parseInt(reader.readLine());
+            int answer = solve(count);
+            System.out.println(answer);
+        }
+    }
+
+    static int solve(int count) {
+        Queue<Integer> queue = new ArrayDeque<>();
+        for (int i = 1; i <= count; i++) {
+            queue.offer(i);
+        }
+
+        while (queue.size() > 1) {
+            // 우선, 제일 위에 있는 카드를 바닥에 버린다.
+            queue.poll();
+
+            // 제일 위에 있는 카드를 제일 아래에 있는 카드 밑으로 옮긴다.
+            Integer number = queue.poll();
+            queue.offer(number);
+        }
+
+        return Objects.requireNonNull(queue.peek());
+    }
+
+}

src/main/java/io/github/imsejin/study/baekjoon/silver/P9012.java

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+package io.github.imsejin.study.baekjoon.silver;
+
+import io.github.imsejin.study.meta.Problem;
+import io.github.imsejin.study.meta.Tag;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.NoSuchElementException;
+
+@Problem(tags = {
+        Tag.DATA_STRUCTURE,
+})
+public class P9012 {
+
+    public static void main(String[] args) throws Exception {
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
+            reader.readLine();
+
+            StringBuilder sb = new StringBuilder();
+            while (true) {
+                String ps = reader.readLine();
+                if (ps == null || ps.isEmpty()) break;
+
+                String answer = solve(ps) ? "YES" : "NO";
+                sb.append(answer).append('\n');
+            }
+
+            System.out.println(sb);
+        }
+    }
+
+    static boolean solve(String ps) {
+        Deque<Character> stack = new ArrayDeque<>();
+
+        try {
+            int length = ps.length();
+            for (int i = 0; i < length; i++) {
+                char c = ps.charAt(i);
+
+                switch (c) {
+                    case '(' -> stack.push(c);
+                    case ')' -> stack.pop();
+                    default -> throw new AssertionError();
+                }
+            }
+        } catch (NoSuchElementException ignored) {
+            return false;
+        }
+
+        return stack.isEmpty();
+    }
+
+}

src/test/groovy/io/github/imsejin/study/baekjoon/silver/P9012Spec.groovy

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+package io.github.imsejin.study.baekjoon.silver
+
+import spock.lang.Specification
+
+class P9012Spec extends Specification {
+
+    def "test"() {
+        when:
+        def actual = P9012.solve(parenthesisString)
+
+        then:
+        actual == expected
+
+        where:
+        parenthesisString       | expected
+        "(())())"               | false
+        "(((()())()"            | false
+        "((()()(()))(((())))()" | false
+        "(()((())()("           | false
+        "(("                    | false
+        "))"                    | false
+        "())(()"                | false
+        "(()())((()))"          | true
+        "()()()()(()()())()"    | true
+    }
+
+}