1 #include <iostream>
2 #include <algorithm>
3 #include <
set>
4 using namespace std;
5
6 int main()
7 {
8 ios::sync_with_stdio(
false);
9 cin.tie(
0);
10 int n;
11 cin >>
n;
12 set<
int>
s;
13 for (
int i =
0; i < n; i++
) {
14 int x;
15 cin >>
x;
16 s.insert(x <
0 ? -
x : x);
17 }
18 cout << n - s.size() <<
endl;
19 return 0;
20 }
转载于:https://www.cnblogs.com/AntonLiu/p/11161433.html
