Sort Array By Parity

September 15, 2019 by Sandeep Bhardwaj | Tags:


Sort Array By Parity

/**
 * 905. Sort Array By Parity
 * Given an array A of non-negative integers, return an array consisting of all the even elements of A, followed by all the odd elements of A.
 * <p>
 * You may return any answer array that satisfies this condition.
 * <p>
 * Example 1:
 * <p>
 * Input: [3,1,2,4]
 * Output: [2,4,3,1]
 * The outputs [4,2,3,1], [2,4,1,3], and [4,2,1,3] would also be accepted.
 * <p>
 * Note:
 * <p>
 * 1 <= A.length <= 5000
 * 0 <= A[i] <= 5000
 * <p>
 */
public class SortArrayByParity {

	public int[] sortArrayByParity(int[] A) {
		int left = 0;
		int right = A.length - 1;

		while (left <= right) {
			//swap and increment
			if (A[left] % 2 != 0 && A[right] % 2 == 0) {
				int temp = A[left];
				A[left] = A[right];
				A[right] = temp;

				left++;
				right--;
			}

			if (A[left] % 2 == 0) {
				left++;
			}
			if (A[right] % 2 != 0) {
				right--;
			}
		}
		return A;
	}
}