Remove duplicates from sorted array, palindrome number - Leetcode solution in python

Solution  for leetcode problems - Remove duplicates from sorted array and palindrome number in python


1. Remove duplicates from sorted array

Given an integer array, nums sorted in non-decreasing order, remove the duplicates in place such that each unique element appears only once. The relative order of the elements should be kept the same.

Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements.

Return k after placing the final result in the first k slots of nums.

Do not allocate extra space for another array. You must do this by modifying the input array in-place with O(1) extra memory.

Custom Judge:

The judge will test your solution with the following code:

int[] nums = [...]; // Input array

int[] expectedNums = [...]; // The expected answer with correct length

int k = removeDuplicates(nums); // Calls your implementation

assert k == expectedNums.length;

for (int i = 0; i < k; i++) {

    assert nums[i] == expectedNums[i];

}

If all assertions pass, then your solution will be accepted.

Example 1:

Input: nums = [1,1,2]

Output: 2, nums = [1,2,_]

Explanation: Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively.

It does not matter what you leave beyond the returned k (hence they are underscores).

Example 2:

Input: nums = [0,0,1,1,1,2,2,3,3,4]

Output: 5, nums = [0,1,2,3,4,_,_,_,_,_]

Explanation: Your function should return k = 5, with the first five elements of nums being 0, 1, 2, 3, and 4 respectively.

It does not matter what you leave beyond the returned k (hence they are underscores).

Constraints:

0 <= nums.length <= 3 * 104

-100 <= nums[i] <= 100

nums is sorted in non-decreasing order.

Code :

class Solution:

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

        if len(nums) == 0:

            return 0

        cur = 0

        for pos in range(1, len(nums)):

            if nums[pos] != nums[cur]:

                cur += 1

                nums[cur] = nums[pos]

        return cur+1

 

Runtime : 80ms

Memory : 16MB


2. Palindrome number

Given an integer x, return true if x is a palindrome integer.

An integer is a palindrome when it reads the same backward as forward. For example, 121 is palindrome while 123 is not.

Example 1:

Input: x = 121

Output: true

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.

Example 4:

Input: x = -101

Output: false

Constraints:

           -231 <= x <= 231 – 1

Code :

class Solution:

    def isPalindrome(self, x: int) -> bool:

        x=str(x)

        rev=x[::-1]

        if(x==rev):

            return True

        else :

            return False    

Runtime : 44ms

Memory : 14.1MB

 

       

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