将一个排好序的数组中重复的数字删除

思路：维护头和尾指针，头指针始终指向最后一个不重复的数字，尾指针不断向数组尾部探索找到不重复的值之后将其拷贝到头指针

1. class Solution {
2. public:
3. int removeDuplicates(int A[], int n) {
4. if (n <= 1)
5. {
6. return n;
7. }
8. int count = 1, head = 0, tail = 1;
9. while (tail < n)
10. {
11. while (A[tail] == A[head])
12. tail++;
13. if (tail < n)
14. {
15. A[++head] = A[tail++];
16. count++;
17. }
19. }
20. return count;
21. }
22. };