Create 3044-most-frequent-prime.js

Author: everthis

3044-most-frequent-prime.js

@@ -0,0 +1,61 @@
+/**
+ * @param {number[][]} mat
+ * @return {number}
+ */
+var mostFrequentPrime = function (mat) {
+  const DIRS = [
+    [1, 1],
+    [1, -1],
+    [-1, 1],
+    [-1, -1],
+    [1, 0],
+    [0, 1],
+    [-1, 0],
+    [0, -1],
+  ]
+
+  const m = mat.length
+  const n = mat[0].length
+  const f = new Map()
+
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      for (const d of DIRS) {
+        let t = 0
+        for (
+          let k = i, l = j;
+          k >= 0 && k < m && l >= 0 && l < n;
+          k += d[0], l += d[1]
+        ) {
+          t = t * 10 + mat[k][l]
+          f.set(t, (f.get(t) || 0) + 1)
+        }
+      }
+    }
+  }
+
+  let res = -1
+  let maxF = 0
+
+  for (const [val, freq] of f.entries()) {
+    if (val <= 10) continue
+    if (freq >= maxF && isPrime(val)) {
+      if (freq === maxF) {
+        res = Math.max(res, val)
+      } else {
+        res = val
+      }
+      maxF = freq
+    }
+  }
+
+  return res
+}
+function isPrime(N) {
+  if (N < 2) return false
+  const R = Math.sqrt(N)
+  for (let d = 2; d <= R; ++d) {
+    if (N % d === 0) return false
+  }
+  return true
+}