905. Sort Array By Parity

Problem Link

Description

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Given an integer array nums, move all the even integers at the beginning of the array followed by all the odd integers.

Return any array that satisfies this condition.

 

Example 1:

Input: nums = [3,1,2,4]
Output: [2,4,3,1]
Explanation: The outputs [4,2,3,1], [2,4,1,3], and [4,2,1,3] would also be accepted.

Example 2:

Input: nums = [0]
Output: [0]

 

Constraints:

• 1 <= nums.length <= 5000
• 0 <= nums[i] <= 5000

Solution

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Python3

class Solution:
    def sortArrayByParity(self, nums: List[int]) -> List[int]:
        i = 0
 
        for j, x in enumerate(nums):
            if x % 2 == 0:
                nums[i], nums[j] = nums[j], nums[i]
                i += 1
        
        return nums

C++

class Solution {
public:
    vector<int> sortArrayByParity(vector<int> &A) {
        for (int i = 0, j = 0; j < A.size(); j++)
            if (A[j] % 2 == 0) swap(A[i++], A[j]);
        return A;
    }
};