Merge pull request #1665 from AlgorithmWithGod/zinnnn37

[20251213] BOJ / G2 / 로봇 조종하기 / 김민진

Author: ShinHeeEul

zinnnn37/202512/13 BOJ G2 로봇 조종하기.md

@@ -0,0 +1,77 @@
+```java
+import java.io.*;
+import java.util.Arrays;
+import java.util.StringTokenizer;
+
+public class BJ_2169_로봇_조종하기 {
+    private static final int INF = -987654321;
+
+    private static final BufferedReader  br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter  bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static       StringTokenizer st;
+
+    private static int N, M;
+    private static int[] ldp, rdp;
+    private static int[][] matrix, dp;
+
+    public static void main(String[] args) throws IOException {
+        init();
+        sol();
+    }
+
+    private static void init() throws IOException {
+        st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        matrix = new int[N + 1][M + 1];
+        for (int i = 1; i <= N; i++) {
+            st = new StringTokenizer(br.readLine());
+            for (int j = 1; j <= M; j++) {
+                matrix[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        dp = new int[N + 1][M + 1];
+        ldp = new int[M + 2];
+        rdp = new int[M + 2];
+
+        for (int i = 2; i <= N; i++) {
+            Arrays.fill(dp[i], INF);
+        }
+
+        for (int i = 1; i <= M; i++) {
+            dp[1][i] = dp[1][i - 1] + matrix[1][i];
+        }
+    }
+
+    private static void sol() throws IOException {
+        for (int i = 2; i <= N; i++) {
+            clear();
+            for (int j = 1; j <= M; j++) {
+                ldp[j] = matrix[i][j] + Math.max(dp[i - 1][j], ldp[j - 1]);
+            }
+
+            for (int j = M; j > 0; j--) {
+                rdp[j] = matrix[i][j] + Math.max(dp[i - 1][j], rdp[j + 1]);
+            }
+
+            for (int j = 1; j <= M; j++) {
+                dp[i][j] = Math.max(ldp[j], rdp[j]);
+            }
+        }
+
+        bw.write(dp[N][M] + "");
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void clear() {
+        Arrays.fill(ldp, INF);
+        Arrays.fill(rdp, INF);
+    }
+
+}
+```