contains duplicate

Author: JisooPyo

contains-duplicate/JisooPyo.kt

@@ -0,0 +1,38 @@
+package leetcode_study
+
+import io.kotest.matchers.shouldBe
+import org.junit.jupiter.api.Test
+
+/**
+ * Leetcode
+ * 217. Contains Duplicate
+ * Easy
+ */
+class ContainsDuplicate {
+    /**
+     * Runtime: 17 ms(Beats: 80.99 %)
+     * Time Complexity: O(n)
+     *   - 배열 순회
+     *
+     * Memory: 50.63 MB(Beats: 70.32 %)
+     * Space Complexity: O(n)
+     *   - HashSet에 최악의 경우 배열 원소 모두 저장
+     */
+    fun containsDuplicate(nums: IntArray): Boolean {
+        val set = hashSetOf<Int>()
+        for (i in nums) {
+            if (set.contains(i)) {
+                return true
+            }
+            set.add(i)
+        }
+        return false
+    }
+
+    @Test
+    fun test() {
+        containsDuplicate(intArrayOf(1, 2, 3, 1)) shouldBe true
+        containsDuplicate(intArrayOf(1, 2, 3, 4)) shouldBe false
+        containsDuplicate(intArrayOf(1, 1, 1, 3, 3, 4, 3, 2, 4, 2)) shouldBe true
+    }
+}