RemoveElement.java

package easy._27;

/**
 * @author Larry
 *
 * Given an array nums and a value val, remove all instances of that value in-place and return the new length.
 * Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
 * The order of elements can be changed. It doesn't matter what you leave beyond the new length.
 *
 * Example 1:
 *        Given nums = [3,2,2,3], val = 3,
 *        Your function should return length = 2, with the first two elements of nums being 2.
 *        It doesn't matter what you leave beyond the returned length.
 *
 * Example 2:
 *        Given nums = [0,1,2,2,3,0,4,2], val = 2,
 *        Your function should return length = 5, with the first five elements of nums containing 0, 1, 3, 0, and 4.
 *        Note that the order of those five elements can be arbitrary.
 *        It doesn't matter what values are set beyond the returned length.
 *
 * Clarification:
 *
 * Confused why the returned value is an integer but your answer is an array?
 * Note that the input array is passed in by reference, which means modification to the input array will be known to the caller as well.
 * Internally you can think of this:
 * // nums is passed in by reference. (i.e., without making a copy)
 *        int len = removeElement(nums, val);
 *
 * // any modification to nums in your function would be known by the caller.
 * // using the length returned by your function, it prints the first len elements.
 *        for (int i = 0; i < len; i++) {
 *        print(nums[i]);
 *        }
 */

public class RemoveElement {

    public int removeElement(int[] nums, int val) {

        int len = 0;

        for (int i = 0; i < nums.length; i ++) {
            if (nums[i] != val) {
                nums[len] = nums[i];
                len ++;
            }

        }

        return len;

    }
    
}