Given an array and a value, 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 in place with constant memory.
The order of elements can be changed. It doesn't matter what you leave beyond the new length.
Example:
Given input arraynums=[3,2,2,3],val=3
Your function should return length = 2, with the first two elements ofnumsbeing 2.
Hint:
Try two pointers.
Did you use the property of "the order of elements can be changed"?
What happens when the elements to remove are rare?
再重复一边， easy的题都不难， 但是要保持脑袋清醒冷静。 否则容易掉到沟里。
