4-3

27. remove elements

Given an array nums and a value val, you need to place the elements to remove all equal values ​​val, and returns the new length of the array after removal.

Do not use extra space for an array, you must modify the input array in place and completed under the conditions of use O (1) extra space.

Order of the elements may be changed. You do not need to consider beyond the elements of the new array length behind.

Example 1:

给定 nums = [3,2,2,3], val = 3,

函数应该返回新的长度 2, 并且 nums 中的前两个元素均为 2。

你不需要考虑数组中超出新长度后面的元素。
Example 2:

给定 nums = [0,1,2,2,3,0,4,2], val = 2,

函数应该返回新的长度 5, 并且 nums 中的前五个元素为 0, 1, 3, 0, 4。

注意这五个元素可为任意顺序。

你不需要考虑数组中超出新长度后面的元素。
Description:

Why return value is an integer, but the answer is an array of output it?

Please note that the input array is passed by "reference" mode, which means to modify the input array is visible to the caller within the function.

You can imagine the internal operation is as follows:

// nums 是以“引用”方式传递的。也就是说，不对实参作任何拷贝
int len = removeElement(nums, val);

// 在函数里修改输入数组对于调用者是可见的。
// 根据你的函数返回的长度, 它会打印出数组中该长度范围内的所有元素。
for (int i = 0; i < len; i++) {
print(nums[i]);
}

My solution:

class Solution(object):
    def removeElement(self, nums, val):
        """
        :type nums: List[int]
        :type val: int
        :rtype: int
        """
        while val in nums:
            nums.remove(val)
        return len(nums)

analysis:

list can also be used in the method;

Use the remove method to delete the specified element in the list.