vector <int> nums = {1, 1, 3, 3, 6, 10, 12, 12};
auto element = unique(nums.begin(), nums.end());
auto begin = nums.begin();
int result = element - begin;
cout << *element << endl; //10
cout << *begin << endl; //1
cout << el << endl; //5 unique numbers in the vector
cout << &element << endl;//0x7fffb577ed88
cout << &begin << endl; //0x7fffb577ed90
我们怎么得到5？如果唯一的地址(nums.begin(),nums.end())是0x7ffebffb288,地址是nums.begin()= 0x7ffebffb2850？
一定是8,一定不是吗？