Java Algorithm

Author: par3k

BOJ_JAVA/out/production/BOJ_JAVA/SWEA/Solution_1949.class

@@ -0,0 +1,89 @@
+package SWEA;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class Solution_1949 {
+    private static int N, K, maxLen, maxHigh;
+    private static int[][] graph;
+    private static boolean[][] visited;
+    private static int[] dx = {-1 ,1, 0, 0};
+    private static int[] dy = {0, 0, -1, 1};
+
+    private static void DFS(int x, int y, int h, int l, int cnt) {
+        for (int dir = 0; dir < 4; dir++) {
+            if (maxLen < l) maxLen = l;
+
+            int nx = x + dx[dir];
+            int ny = y + dy[dir];
+
+            if (0 <= nx && nx < N && 0 <= ny && ny < N && !visited[nx][ny]) {
+               if (h <= graph[nx][ny]) {
+                   if (cnt == 0) {
+                       if (h > graph[nx][ny] - K) {
+                           visited[nx][ny] = true;
+                           DFS(nx, ny, h - 1, l + 1, cnt + 1);
+                           visited[nx][ny] = false;
+                       }
+                   }
+               } else {
+                   visited[nx][ny] = true;
+                   DFS(nx, ny, graph[nx][ny], l + 1, cnt);
+                   visited[nx][ny] = false;
+               }
+            }
+        }
+    }
+
+
+    private static void Solution() {
+        for (int i = 0; i < N; i++) {
+            for (int j = 0 ;j  < N; j++) {
+                if (graph[i][j] == maxHigh) {
+                    visited[i][j] = true;
+                    DFS(i, j, maxHigh, 1, 0);
+                    visited[i][j] = false;
+                }
+            }
+        }
+    }
+
+
+
+    private static void input() throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+        int T = Integer.parseInt(br.readLine());
+
+        for (int tc = 1; tc <= T; tc++) {
+            String[] line = br.readLine().split(" ");
+            N = Integer.parseInt(line[0]);
+            K = Integer.parseInt(line[1]);
+            maxLen = maxHigh = 0;
+            graph = new int[N][N];
+            visited = new boolean[N][N];
+
+
+            for (int i = 0 ; i < N; i++) {
+                StringTokenizer st = new StringTokenizer(br.readLine());
+                for (int j = 0; j < N; j++) {
+                    graph[i][j] = Integer.parseInt(st.nextToken());
+                    if (maxHigh < graph[i][j]) {
+                        maxHigh = graph[i][j];
+                    }
+                }
+            }
+            Solution();
+            sb.append("#").append(tc).append(" ").append(maxLen).append("\n");
+        }
+        System.out.println(sb.toString());
+        br.close();
+
+    }
+
+    public static void main(String[] args) throws Exception {
+        input();
+    }
+}