27. 移除元素

27. 移除元素 - 力扣（Leetcode）

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import java.util.Scanner;

//27 移除元素
class RemoveElement27 {
	public static void main (String[] args) {
		Scanner myScanner = new Scanner(System.in);
		int[] numArray = {0,1,2,3,3,0,4,2};
		System.out.print("请输入要去除的元素：");
		int removeNum = myScanner.nextInt();
		//int newLength = removeElement(numArray,removeNum);
		int newLength = removeElement02(numArray,removeNum);
		System.out.println("\nThe length of the new numArray is " + newLength);
		myScanner.close();
	}
	//双指针法
	public static int removeElement(int[] nums,int val){
		int slowIndex = 0;
		for (int fastIndex = 0; fastIndex < nums.length; fastIndex++){
			if (nums[fastIndex] != val) {
				nums[slowIndex] = nums[fastIndex];
				slowIndex++;
			}
		}
		return slowIndex;
	}
	//相向双指针法
	public static int removeElement02(int[] nums,int val){
		int left = 0;
		int right = nums.length - 1;
		//找到从右边开始第一个会被交换过来的元素作为第一个交换的
		while(right >= 0 && nums[right] == val) right--;
		while(left <= right){
			if (nums[left] == val) {
				nums[left] = nums[right--];
			}
			left++;
			while(right >= 0 && nums[right] == val) right--;
		}
		return left;
	}
}

Bug:

solution：文件名要和类名保持一致。