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Leetcode with dani
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Leetcode with dani pinned «#leet_code_Q1 #Array Given a non-empty array of integers nums, every element appears twice except for one. Find that single one. You must implement a solution with a linear runtime complexity and use only constant extra space. Example 1: Input: nums…»
Hint2: try Xor operation
lets submit our code
it's good. we did better from 78 % of submitted code in python by running time
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Level Up Problem-Solving: LeetCode trains your brain to break down problems, a skill used by 80% of software engineers according to a [Payscale survey]( Indeed salary survey for Software Engineer).
lets do another Question on Leet code
#leet_code_Q2 #Array #leet_code_169 #Majority_Element Given an array nums of size n, return the majority element.

The majority element is the element that appears more than (n / 2)times. You may assume that the majority element always exists in the array.

Example 1:

Input: nums = [3,2,3]
Output: 3
Example 2:

Input: nums = [2,2,1,1,1,2,2]
Output: 2
Let's tackle the question of finding the number that appears only once in a list.

if you want to figure it out your self, dont see the answer!!!!!!!!!!!!!!!!!!

We could iterate through the list, comparing each element to all others to count occurrences. This approach would work, but it has a time complexity of n^2, exceeding the given constraint of linear time (O(n)).



Since the question guarantees that all other elements appear twice, we can exploit this property. Here's how:



Convert the list to a set. Sets eliminate duplicates, leaving only the unique element.

Calculate the sum of the elements in the original list and the set.

Unique number = Sum of list elements - (2 * Sum of set elements)

This method efficiently finds the unique element in linear time.



There's an even better approach called the XOR method. If you'd like an explanation of how it works, I can provide the code and break it down for you class Solution:

def singleNumber(self, nums: List[int]) -> int:

result = 0

for i in nums:

result^=i

return result
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Forwarded from Leetcode with dani
it's good. we did better from 78 % of submitted code in python by running time
🎉2
Leetcode with dani pinned «#leet_code_Q2 #Array #leet_code_169 #Majority_Element…»
Leetcode with dani
#leet_code_Q2 #Array #leet_code_169 #Majority_Element…
give me your ideas about this question. how can we solve it???
so let's tackle this question. so how can we know the element is maority element ,if it is the most frequent element in the array yea . so we can calculate each element freaquency by creating a dictionary like this my_dicti = {} for i in nums: if nums[i] in my_dict: my_dict[i] +=1 else: my_dict[i] = 1 and we can print the find the maximum frequent number in the dictionary and return it but there is also another efficient method to do it by declearing two variabes one to contain the number and the second to cotain it's occurence like this
nums = [1,2,3,4,5,4,4,3]
contain = nums[0]
occurence = 0
for i in nums:
if i == contain:
occurence += 1
else:
if occurence == 0:
contain = i
occurence =1
else:
occurence -= 1
557. Reverse Words in a String III Given a string s, reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.
Example 1:

Input: s = "Let's take LeetCode contest"
Output: "s'teL ekat edoCteeL tsetnoc"
Example 2:

Input: s = "Mr Ding"
Output: "rM gniD" #leet_code_Q3 #String
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9. Palindrom number #leet_code_Q4 #math #my_twopointer Given an integer x, return true if x is a
palindrome, and false otherwise.
Example 1:
Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.
Example 2:
Input: x = -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
Example 3:
Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.