LeetCode #217 Contains Duplicate 包含重複項目

public class Solution {
    public bool ContainsDuplicate(int[] nums) {
        for(int i = 0;i<nums.Length;i++)
        {
            if(Array.IndexOf(nums, nums[i],i+1)!=-1)
            {
                return true;
            }
        }
        return false;
    }
}

public class Solution {
    public bool ContainsDuplicate(int[] nums) {
        HashSet<int> hSet = new HashSet<int>();
        
        for(int i = 0;i<nums.Length;i++)
        {
            if(hSet.Contains(nums[i]))
            {
                return true;
            }
            hSet.Add(nums[i]);
        }
        return false;
    }
}

public class Solution {
    public bool ContainsDuplicate(int[] nums) {
        Array.Sort(nums);
        
        for(int i = 0;i<nums.Length-1;i++)
        {
            if(nums[i]==nums[i+1])
            {
                return true;
            }
        }
        return false;
    }
}

class Solution {
    public boolean containsDuplicate(int[] nums) {
        HashSet<Integer> hSet = new HashSet<Integer>();
        
        for(int i = 0;i<nums.length;i++)
        {
            if(hSet.contains(nums[i]))
            {
                return true;
            }
            hSet.add(nums[i]);
        }
        return false;
    }
}

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        s = set()
        
        for i in range(len(nums)):
            if(nums[i] in s):
                return True
            s.add(nums[i])
            
        return False

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        d = {}  #dict
        
        for i in range(len(nums)):
            if(nums[i] in d):
                return True
            d[nums[i]] = 0
            
        return False

/**
 * @param {number[]} nums
 * @return {boolean}
 */
var containsDuplicate = function(nums) {
    var set = new Set();
    for(var i = 0;i<nums.length;i++)
    {
        if(set.has(nums[i]))
        {
            return true;
        }
        set.add(nums[i]);
    }
    return false;
};

/**
 * @param {number[]} nums
 * @return {boolean}
 */
var containsDuplicate = function(nums) {
    nums.sort();
    for(var i=0; i<nums.length-1;i++)
    {
        if(nums[i] == nums[i+1]) 
        {
            return true;
        }
    }
    return false;
};