Create 2768-number-of-black-blocks.js

Author: everthis

2768-number-of-black-blocks.js

@@ -0,0 +1,48 @@
+/**
+ * @param {number} m
+ * @param {number} n
+ * @param {number[][]} coordinates
+ * @return {number[]}
+ */
+const countBlackBlocks = function (m, n, coordinates) {
+  let arr = new Array(5).fill(0)
+  arr[0] = (m - 1) * (n - 1)
+  let mat = {}
+  for (let [r, c] of coordinates) {
+    mat[r] ||= []
+    mat[r][c] = true
+  }
+  for (let [r, c] of coordinates) {
+    for (let i = -1; i < 1; i++) {
+      for (let j = -1; j < 1; j++) {
+        let nextR = r + i
+        let nextC = c + j
+        if (nextR < 0 || nextC < 0 || (nextR >= m - 1) | (nextC >= n - 1))
+          continue
+        let res = getRes(nextR, nextC, mat)
+        arr[res]++
+      }
+    }
+  }
+  for (let i = 1; i < 5; i++) {
+    arr[i] = ~~(arr[i] / i)
+  }
+  let used = 0
+  for (let i = 1; i < 5; i++) {
+    used += arr[i]
+  }
+  arr[0] -= used
+  return arr
+}
+
+const getRes = (r, c, mat) => {
+  let res = 0
+  for (let i = 0; i < 2; i++) {
+    for (let j = 0; j < 2; j++) {
+      let nextR = r + i
+      let nextC = c + j
+      if (mat[nextR]?.[nextC] === true) res++
+    }
+  }
+  return res
+}