961. N-Repeated Element in Size 2N Array (axross#128)

Author: Kohei Asai

solutions/n_repeated_element_in_size_2n_array.ts

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+// 961. N-Repeated Element in Size 2N Array
+// https://leetcode.com/problems/n-repeated-element-in-size-2n-array/submissions/
+export default function repeatedNTimes<T>(A: T[]): T {
+  const found = new Set();
+
+  for (const value of A) {
+    if (found.has(value)) return value;
+
+    found.add(value);
+  }
+
+  throw new Error("unreachable here");
+}

solutions/n_repeated_element_in_size_2n_array_test.ts

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+import { test } from "https://deno.land/std/testing/mod.ts";
+import { assertStrictEq } from "https://deno.land/std/testing/asserts.ts";
+import repeatedNTimes from "./n_repeated_element_in_size_2n_array.ts";
+
+test("961. N-Repeated Element in Size 2N Array", () => {
+  assertStrictEq(repeatedNTimes([1, 2, 3, 3]), 3);
+  assertStrictEq(repeatedNTimes([2, 1, 2, 5, 3, 2]), 2);
+  assertStrictEq(repeatedNTimes([2, 1, 2, 5, 3, 2]), 2);
+  assertStrictEq(repeatedNTimes([5, 1, 5, 2, 5, 3, 5, 4]), 5);
+});