[20250916] BOJ / P5 / 오아시스 재결합 / 김민진

zinnnn37/202509/16 BOJ P5 오아시스 재결합.md

@@ -0,0 +1,58 @@
+```java
+import java.io.*;
+import java.util.Stack;
+
+public class BJ_3015_오아시스_재결합 {
+
+	private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+	private static int  N;
+	private static long ans;
+
+	private static Stack<Node> s;
+
+	private static class Node {
+		int val;
+		int cnt;
+
+		Node(int val, int cnt) {
+			this.val = val;
+			this.cnt = cnt;
+		}
+	}
+
+	public static void main(String[] args) throws IOException {
+		sol();
+	}
+
+	private static void sol() throws IOException {
+		N = Integer.parseInt(br.readLine());
+		s = new Stack<>();
+
+		ans = 0;
+		for (int i = 0; i < N; i++) {
+			int  n   = Integer.parseInt(br.readLine());
+			Node cur = new Node(n, 1);
+
+			while (!s.isEmpty() && s.peek().val <= cur.val) {
+				Node prev = s.pop();
+
+				ans += prev.cnt;
+				if (prev.val == cur.val) {
+					cur.cnt += prev.cnt;
+				}
+			}
+			if (!s.isEmpty()) {
+				ans++;
+			}
+			s.push(cur);
+		}
+		bw.write(ans + "\n");
+		bw.flush();
+		bw.close();
+		br.close();
+	}
+
+}
+```