고층 건물 (#82)

Author: asqwklop12

pr/고층 건물/Main.java

@@ -0,0 +1,72 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) {
+        new Main().run();
+    }
+    public void run() {
+        FastReader fr = new FastReader();
+                int n = Integer.parseInt(fr.next());
+        long[] arr = new long[n];
+        for(int i=0; i<n; i++) arr[i] = Long.parseLong(fr.next());
+        this.n = n;
+        this.arr = arr;
+        System.out.println(this.solve(n, arr));
+    }
+    public int n;
+    public long[] arr;
+    public long max = Long.MIN_VALUE;
+
+    /**
+     * 문제 해결 메서드
+     * 
+     * @param 문제에 맞는 파라미터들
+     * @return 문제에 맞는 반환 타입
+     */
+    public long solve(int n, long[] arr) {
+        for (int i = 0; i < n; i++) {
+            long total = left(i) + right(i);
+            max = Math.max(max, total);
+        }
+
+        return max;
+    }
+
+    public long right(int cur) {
+        int count = 0;
+        double maxSlope = Double.MIN_VALUE;
+        for (int next = cur + 1; next < n; next++) {
+            double slope = (double) (arr[next] - arr[cur]) / (next - cur);
+            if (next == cur + 1 || maxSlope < slope) {
+                count++;
+                maxSlope = slope;
+            }
+        }
+
+        return count;
+    }
+
+    public long left(int cur) {
+        int count = 0;
+        double minScope = Double.MAX_VALUE;
+        for (int prev = cur - 1; prev >= 0; prev--) {
+            double slope = (double) (arr[prev] - arr[cur]) / (prev - cur);
+
+            if (prev == cur - 1 || minScope > slope) {
+                count++;
+                minScope = slope;
+            }
+        }
+        return count;
+    }
+
+    static class FastReader {
+        BufferedReader br; StringTokenizer st;
+        public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); }
+        public String next() { while (st == null || !st.hasMoreElements()) { try { st = new StringTokenizer(br.readLine()); } catch (IOException e) { } } return st.nextToken(); }
+        public int nextInt() { return Integer.parseInt(next()); }
+        public long nextLong() { return Long.parseLong(next()); }
+        public boolean hasMoreTokens() { while (st == null || !st.hasMoreElements()) { String line = null; try { line = br.readLine(); } catch (IOException e) { } if (line == null) return false; st = new StringTokenizer(line); } return true; }
+    }
+}