0217 - Contains Duplicate

Description (leetcode)

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

Explanation:

The element 1 occurs at the indices 0 and 3.

Example 2:

Input: nums = [1,2,3,4]

Output: false

Explanation:

All elements are distinct.

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

submission

impl Solution {
    pub fn contains_duplicate(nums: Vec<i32>) -> bool {
        nums.len()
            != nums
                .iter()
                .copied()
                .collect::<std::collections::HashSet<i32>>()
                .len()
    }
}