Create 2088-count-fertile-pyramids-in-a-land.js

Author: everthis

2088-count-fertile-pyramids-in-a-land.js

@@ -0,0 +1,48 @@
+/**
+ * @param {number[][]} grid
+ * @return {number}
+ */
+const countPyramids = function(grid) {
+  const rev = clone(grid)
+  let res = count(grid)
+  rev.reverse()
+  res += count(rev)
+  return res
+
+  function clone(grid) {
+    let res = []
+    for (const row of grid) {
+      res.push(row.slice())
+    }
+    return res
+  }
+  function reverse(grid) {
+    let l = 0, r = grid.length - 1
+    while(l < r) {
+      const tmp = grid[l]
+      grid[l] = grid[r]
+      grid[r] = tmp
+      l++
+      r--
+    }
+  }
+
+  function count(grid) {
+    const m = grid.length, n = grid[0].length
+    let res = 0
+
+    for (let i = 1; i < m; i++) {
+      for (let j = 1; j < n - 1; j++) {
+        if (grid[i][j] && grid[i - 1][j]) {
+          grid[i][j] = Math.min(
+            grid[i - 1][j - 1],
+            grid[i - 1][j + 1]
+          ) + 1
+          res += grid[i][j] - 1
+        }
+      }
+    }
+
+    return res
+  }
+};