[LeetCode] Remove Element

Given an array and a value, remove all instances of that value in place and return the new length.

The order of elements can be changed. It doesn't matter what you leave beyond the new length.

idx 指向不是重复的数组的最后索引，双指针思想

class Solution {
    public:
        int removeElement(int A[], int n, int elem)
        {   
            if(A == NULL)
                return 0;
            int idx = 0;
            cout << "n:" << n<< endl;
            for(int i = 0; i < n; i++)
            {   
                cout << idx << endl;
                if(A[i] != elem)
                {   
                    A[idx++] = A[i];
                }   

            }   
            return idx;

        }   
};