게임개발

pr/게임개발/Main.java

@@ -0,0 +1,138 @@
+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());
+        List<Integer>[] buildingInfo = new ArrayList[n];
+        for (int i = 0; i < n; i++) {
+            buildingInfo[i] = new ArrayList<>();
+            while (fr.hasMoreTokens()) {
+                int val = Integer.parseInt(fr.next());
+                buildingInfo[i].add(val);
+                if (val == -1)
+                    break;
+            }
+        }
+        int[] results = solve(n, buildingInfo);
+        StringBuilder sb = new StringBuilder();
+        for (int res : results) {
+            sb.append(res).append("\n");
+        }
+        System.out.print(sb.toString());
+    }
+
+    static class Building {
+        int index;
+        int time;
+
+        List<int[]> prevBuildings;
+
+        public Building(int index, int time) {
+            this.index = index;
+            this.time = time;
+            this.prevBuildings = new ArrayList<>();
+        }
+
+        public void addPrevBuilding(int prevBuilding, int time) {
+            this.prevBuildings.add(new int[] { prevBuilding, time });
+        }
+    }
+
+    int[] memo;
+    List<Building> buildings = new ArrayList<>();
+
+    /**
+     * 문제 해결 메서드
+     * 
+     * @param n            건물의 개수
+     * @param buildingInfo 각 줄의 정보 (시간, 선행 건물들, -1이 포함된 리스트 배열)
+     * @return 각 건물이 완성되는 최소 시간 배열
+     */
+    public int[] solve(int n, List<Integer>[] buildingInfo) {
+        // buildingInfo[i]는 {시간, 선행1, 선행2, ..., -1} 형태의 List입니다.
+
+        memo = new int[n];
+        Arrays.fill(memo, -1);
+        buildings = new ArrayList<>();
+
+        for (int i = 0; i < n; i++) {
+            buildings.add(new Building(i, buildingInfo[i].get(0)));
+
+            for (int k = 1; k < buildingInfo[i].size(); k++) {
+                int prevBuilding = buildingInfo[i].get(k);
+                if (prevBuilding == -1)
+                    break;
+                buildings.get(i).addPrevBuilding(prevBuilding - 1, buildingInfo[prevBuilding - 1].get(0));
+            }
+        }
+
+        int[] totalTimes = new int[n];
+        for (int i = 0; i < n; i++) {
+            totalTimes[i] = dfs(i);
+        }
+
+        return totalTimes;
+    }
+
+    public int dfs(int index) {
+        if (memo[index] != -1)
+            return memo[index];
+
+        int maxPrev = 0;
+
+        for (int[] prev : buildings.get(index).prevBuildings) {
+            int prevIdx = prev[0];
+            maxPrev = Math.max(maxPrev, dfs(prevIdx));
+        }
+
+        memo[index] = buildings.get(index).time + maxPrev;
+        return memo[index];
+    }
+
+    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;
+        }
+    }
+}