[20250415] BOJ / G1 / 순열 그래프의 연결성 판별 / 권혁준

Author: oncsr

khj20006/202504/15 BOJ G1 순열 그래프의 연결성 판별.md

@@ -0,0 +1,82 @@
+```java
+
+import java.util.*;
+import java.io.*;
+
+class Main {
+	
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static String nextToken() throws Exception {
+		while(!st.hasMoreTokens()) nextLine();
+		return st.nextToken();
+	}
+	static int nextInt() throws Exception { return Integer.parseInt(nextToken()); }
+	static long nextLong() throws Exception { return Long.parseLong(nextToken()); }
+	static double nextDouble() throws Exception { return Double.parseDouble(nextToken()); }
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+	
+	// Additional field
+	
+	static int N;
+	static int[] A, max;
+	
+	public static void main(String[] args) throws Exception {
+		
+		ready();
+		solve();
+	
+		bwEnd();
+		
+	}
+	
+	static void ready() throws Exception{
+		
+		N = nextInt();
+		A = new int[N+1];
+		for(int i=1;i<=N;i++) A[i] = nextInt();
+		max = new int[N+1];
+
+	}
+	
+	static void solve() throws Exception{
+		
+		for(int i=1;i<=N;i++) max[i] = Math.max(max[i-1], A[i]);
+		
+		int min = -1;
+		Stack<Integer> ans = new Stack<>();
+		ans.add(N+1);
+		for(int i=N;i>=1;) {
+			int j = i, tempMin = A[i];
+			while(j>=1 && max[j] == max[i]) {
+				tempMin = Math.min(tempMin, A[j]);
+				j--;
+			}
+			if(min == -1) min = tempMin;
+			else {				
+				if(max[i] <= min) ans.add(i+1);
+				min = Math.min(min, tempMin);
+			}
+			i = j;
+		}
+		if(!ans.isEmpty() && ans.peek() != 1) ans.add(1);
+		
+		bw.write((ans.size()-1) + "\n");
+		int now = ans.pop();
+		while(!ans.isEmpty()) {
+			int next = ans.pop();
+			bw.write((next-now) + " ");
+			for(int i=now;i<next;i++) bw.write(i + " ");
+			bw.write("\n");
+			now = next;
+		}
+		
+	}
+	
+}
+
+```