update 217.contains-duplicate.java

Author: marklcrns

217.contains-duplicate.java

@@ -0,0 +1,52 @@
+/*
+ * @lc app=leetcode id=217 lang=java
+ *
+ * [217] Contains Duplicate
+ *
+ * https://leetcode.com/problems/contains-duplicate/description/
+ *
+ * algorithms
+ * Easy (56.60%)
+ * Total Accepted:    749.2K
+ * Total Submissions: 1.3M
+ * Testcase Example:  '[1,2,3,1]'
+ *
+ * Given an array of integers, find if the array contains any duplicates.
+ *
+ * Your function should return true if any value appears at least twice in the
+ * array, and it should return false if every element is distinct.
+ *
+ * Example 1:
+ *
+ *
+ * Input: [1,2,3,1]
+ * Output: true
+ *
+ * Example 2:
+ *
+ *
+ * Input: [1,2,3,4]
+ * Output: false
+ *
+ * Example 3:
+ *
+ *
+ * Input: [1,1,1,3,3,4,3,2,4,2]
+ * Output: true
+ *
+ */
+class Solution {
+	public boolean containsDuplicate(int[] nums) {
+
+		HashSet<Integer> set = new HashSet<Integer>();
+
+		for (int i = 0; i < nums.length; ++i) {
+			if (set.contains(nums[i])) {
+				return true;
+			}
+			set.add(nums[i]);
+		}
+
+		return false;
+	}
+}