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 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:
Given nums = [3,2,2,3], val = 3, Your function should return length = 2, with the first two elements of nums being 2.
输出不是val的元素的个数,并把它们放在数组的前n位
class Solution { public: int removeElement(vector<int>& nums, int val) { int j=0; //j代表不是val的元素个数 for(int i=0;i <nums.capacity();i++){ if(nums[i]!=val){ nums[j++]=nums[i]; //把第j个非val的元素放在数组的第j位置 } } return j; } };