feat: 2025-10-30打卡（接雨水）

407.trapping-rain-water-ii.java

@@ -0,0 +1,95 @@
+/*
+ * @lc app=leetcode id=407 lang=java
+ *
+ * [407] Trapping Rain Water II
+ */
+
+// @lc code=start
+class Solution {
+    public int trapRainWater(int[][] heightMap) {
+        PriorityQueue<Node> pq = new PriorityQueue<>((a, b)->{
+            return a.h - b.h;
+        });
+        boolean[][] visited = visited(heightMap);
+        pushBorders(heightMap, visited, pq);
+        int[][] dirs = new int[][] {
+            new int[] {1, 0},
+            new int[] {-1, 0},
+            new int[] {0, 1},
+            new int[] {0,-1}
+        };
+        int cap = 0;
+        while(!pq.isEmpty()) {
+            Node cur = pq.poll();
+            int x, y;
+            for(int i=0; i<dirs.length; i++) {
+                x = cur.r + dirs[i][0];
+                y = cur.c + dirs[i][1];
+                if(x >= 0 && x < heightMap.length && y >= 0 && y < heightMap[0].length  && !visited[x][y]) {
+                    visited[x][y] = true;
+                    int curh = heightMap[x][y];
+                    if(heightMap[x][y] < cur.h) {
+                        cap += cur.h - heightMap[x][y];
+                        curh = cur.h;
+                    }
+                    pq.add(new Node(x, y, curh));
+                }
+            }
+        }
+        return cap;
+    }
+
+
+    private void pushBorders(int[][] hm, boolean[][] visited, PriorityQueue<Node> pq) {
+        int r = hm.length, c = hm[0].length;
+        for(int i=0;i<r;i++) {
+            visited[i][0] = true;
+            visited[i][c-1] = true;
+            pq.add(new Node(i, 0, hm[i][0]));
+            pq.add(new Node(i, c-1, hm[i][c-1]));
+        }
+        for(int i=0;i<c;i++) {
+            if(!visited[0][i]) {
+                visited[0][i] = true;
+                pq.add(new Node(0, i, hm[0][i]));
+            }
+            if(!visited[r-1][i]) {
+                visited[r-1][i] = true;
+                pq.add(new Node(r-1, i, hm[r-1][i]));
+            }
+        }
+    }
+
+    private boolean[][] visited(int[][] heightMap) {
+        boolean[][] v = new boolean[heightMap.length][heightMap[0].length];
+        for(int i=0; i<v.length; i++) {
+            for(int j=0;j<v[0].length;j++) {
+                v[i][j] = false;
+            }
+        }
+        return v;
+    } 
+
+    static class Node {
+        int r, c, h;
+
+        public Node(int r, int c, int h) {
+            this.r = r;
+            this.c = c;
+            this.h = h;
+        }
+    }
+}
+// @lc code=end
+
+// 12 13 1  12
+// 13 4  13 12
+// 13 8  10 12
+// 12 13 12 12
+// 13 13 13 13
+
+// 0  0  0  0
+// 0  9  0  0
+// 0  4  2  0
+// 0  0  0  0
+// 0  0  0  0