pacific-atlantic-water-flow solution

Author: krokerdile

pacific-atlantic-water-flow/krokerdile.js

@@ -0,0 +1,44 @@
+/**
+ * @param {number[][]} heights
+ * @return {number[][]}
+ */
+const pacificAtlantic = (heights) => {
+  const m = heights.length;
+  const n = heights[0].length;
+  const pacific = Array.from({ length: m }, () => Array(n).fill(false));
+  const atlantic = Array.from({ length: m }, () => Array(n).fill(false));
+
+  const dfs = (r, c, visited, prevHeight) => {
+    if (
+      r < 0 || c < 0 || r >= m || c >= n || 
+      visited[r][c] || heights[r][c] < prevHeight
+    ) return;
+
+    visited[r][c] = true;
+
+    dfs(r + 1, c, visited, heights[r][c]);
+    dfs(r - 1, c, visited, heights[r][c]);
+    dfs(r, c + 1, visited, heights[r][c]);
+    dfs(r, c - 1, visited, heights[r][c]);
+  };
+
+  for (let i = 0; i < m; i++) {
+    dfs(i, 0, pacific, heights[i][0]);
+    dfs(i, n - 1, atlantic, heights[i][n - 1]);
+  }
+
+  for (let j = 0; j < n; j++) {
+    dfs(0, j, pacific, heights[0][j]);
+    dfs(m - 1, j, atlantic, heights[m - 1][j]);
+  }
+
+  const result = [];
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      if (pacific[i][j] && atlantic[i][j]) {
+        result.push([i, j]);
+      }
+    }
+  }
+  return result;
+};