solve(leetcode): 217. Contains Duplicate

Author: jestenough

services/leetcode/problems/0217. Contains Duplicate/README.md

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+# 217. Contains Duplicate
+
+Given an integer array nums, return true if any value appears at least twice in the array, and return false if every
+element is distinct.
+
+```
+Example 1:
+
+Input: nums = [1,2,3,1]
+Output: true
+
+Example 2:
+
+Input: nums = [1,2,3,4]
+Output: false
+
+Example 3:
+
+Input: nums = [1,1,1,3,3,4,3,2,4,2]
+Output: true
+```
+
+Constraints:
+
+```
+    1 <= nums.length <= 105
+    -109 <= nums[i] <= 109
+```
+
+[Problem link](https://leetcode.com/problems/contains-duplicate/)

services/leetcode/problems/0217. Contains Duplicate/src/go.mod

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+module src
+
+go 1.20

services/leetcode/problems/0217. Contains Duplicate/src/solution.go

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+package src
+
+func ContainsDuplicate(nums []int) bool {
+	uniqueNumbers := make(map[int]bool)
+	for _, num := range nums {
+		if _, ok := uniqueNumbers[num]; ok {
+			return true
+		} else {
+			uniqueNumbers[num] = true
+		}
+	}
+
+	return false
+}