feat(0217): Contains Duplicate

Author: zangbianxuegu

0217. Contains Duplicate.js

@@ -0,0 +1,47 @@
+// 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: truea
+
+
+// 1) indexOf
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+const containsDuplicate = function(nums) {
+  for (let i = 0; i < nums.length; i++) {
+    if (nums.indexOf(nums[i]) !== i) {
+      return true
+    }
+  }
+  return false
+}
+// Runtime: 3180 ms, faster than 5.01% of JavaScript online submissions for Contains Duplicate.
+// Memory Usage: 37.6 MB, less than 94.12% of JavaScript online submissions for Contains Duplicate.
+
+
+// 2) Set
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+const containsDuplicate = function(nums) {
+  return [...new Set(nums)].length !== nums.length
+}
+// Runtime: 76 ms, faster than 53.55% of JavaScript online submissions for Contains Duplicate.
+// Memory Usage: 39.6 MB, less than 88.24% of JavaScript online submissions for Contains Duplicate.