双指针例题1

using namespace std;
int (vector<int> a) {
	int num = 1;
	int pre = abs(a[0]);
	int n = a.size();
	int i = 0, j = n-1;
	while (i < j) {
		if (a[i] > a[j]) {
			if (pre != abs(a[i])) {
				pre = abs(a[i]);
				num++;
			}
			i++;
		} else {
			if (pre != abs(a[j])) {
				pre = abs(a[j]);
				num++;
			}
			j--;
		}
	}
	return num;
}
int main()
{
	int v[] =  {-5,-3,-1,1,1,2};
  	vector<int> a (v, v + 6);
	int num = func(a);
	cout<<num<<endl;
}