Leetcode_array.md

268. Missing Number

class Solution:
    def missingNumber(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        nums.sort()
        miss_v = len(nums)
        for i,j in enumerate(nums):
            #using XOR
            miss_v ^= i^j
        return miss_v

217. Contains Duplicate

class Solution:
    def containsDuplicate(self, nums):
        """
        :type nums: List[int]
        :rtype: bool
        """
        nums.sort()
        for i in range(len(nums)-1):
            if nums[i+1]- nums[i] ==0:
                return True
        return False

122. Best Time to Buy and Sell Stock II

class Solution:
   def maxProfit(self, prices):
       """
       :type prices: List[int]
       :rtype: int
       """
       profit = 0
       for i in range(len(prices)-1):
           profit += max(0,prices[i+1]-prices[i])
       return profit

169. Majority Element

class Solution:
   def majorityElement(self, nums):
       """
       :type nums: List[int]
       :rtype: int
       """
       s = set(nums)
       for i in s:            
           if nums.count(i) > len(nums)/2:
               return i

283. Move Zeroes

class Solution:
   def moveZeroes(self, nums):
       """
       :type nums: List[int]
       :rtype: void Do not return anything, modify nums in-place instead.
       """
       for i in nums:
           if i == 0:
               nums.remove(i)
               nums.append(0)
               

121. Best Time to Buy and Sell Stock

class Solution:
   def maxProfit(self, prices):
       """
       :type prices: List[int]
       :rtype: int
       """
       min_price,max_profit = float('inf'),0
       for price in prices:
           min_price = min(price,min_price)
           max_profit = max(max_profit,price-min_price)
       return max_profit