Programmers_250136 : 석유 시추

Author: spring0913

week12/Programmers_250136(석유 시추).java

@@ -0,0 +1,63 @@
+import java.util.*;
+
+class Solution {
+    private int[][] visited;
+    private int oilNum;
+    private Map<Integer, Integer> oilMap;
+    private int[][] land;
+
+    public int solution(int[][] _land) {
+        int answer = 0;
+        land = _land;
+        visited = new int[land.length][land[0].length];
+        oilNum = 1;
+        oilMap = new HashMap<>();
+        for(int i=0; i<land.length; i++) {
+            for(int j=0; j<land[0].length; j++) {
+                if(land[i][j] == 1 && visited[i][j] == 0) {
+                    bfs(i, j);
+                }
+            }
+        }
+        for(int i=0; i<land[0].length; i++) {
+            boolean[] check = new boolean[oilNum];
+            int count = 0;
+            for(int j=0; j<land.length; j++) {
+                int num = visited[j][i];
+                if(num > 0 && !check[num]) {
+                    check[num] = true;
+                    count += oilMap.get(num);
+                }
+            }
+            answer = Math.max(answer, count);
+        }
+        return answer;
+    }
+
+    public void bfs(int startH, int startW) {
+        int[] dh = {0, 1, 0, -1};
+        int[] dw = {-1, 0, 1, 0};
+        Queue<int[]> q = new LinkedList<>();
+        q.offer(new int[]{startH, startW});
+        visited[startH][startW] = oilNum;
+        int count = 1;
+        while(!q.isEmpty()) {
+            int h = q.peek()[0];
+            int w = q.peek()[1];
+            q.poll();
+            for(int i=0; i<4; i++) {
+                int nextH = h + dh[i];
+                int nextW = w + dw[i];
+                if(nextH >= 0 && nextH < land.length && nextW >= 0 && nextW < land[0].length) {
+                    if(land[nextH][nextW] == 1 && visited[nextH][nextW] == 0) {
+                        visited[nextH][nextW] = oilNum;
+                        q.offer(new int[]{nextH, nextW});
+                        count++;
+                    }
+                }
+            }
+        }
+        oilMap.put(oilNum, count);
+        oilNum++;
+    }
+}