✨ check if array pairs are divisible by k

Author: tangweikun

src/1497-check-if-array-pairs-are-divisible-by-k/index.js

@@ -0,0 +1,23 @@
+/**
+ * @param {number[]} arr
+ * @param {number} k
+ * @return {boolean}
+ */
+var canArrange = function (arr, k) {
+  const mod = Array(k).fill(0);
+
+  for (let i = 0; i < arr.length; i++) {
+    mod[((arr[i] % k) + k) % k]++;
+  }
+
+  for (let i = 1; i + i < k; i++) {
+    if (mod[i] !== mod[k - i]) {
+      return false;
+    }
+  }
+
+  return mod[0] % 2 === 0;
+};
+
+canArrange([1, 2, 3, 4, 5, 10, 6, 7, 8, 9], 5);
+canArrange([-1, 1, -2, 2, -3, 3, -4, 4], 3);