算法1
参考文献:摘抄基础课中离散化那一节的代码
C++ 代码
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
int n;
vector<int> alls;
cin>>n;
for(int i = 0; i<n;i++)
{
int k;
cin>>k;
alls.push_back(k);
}
sort(alls.begin(), alls.end());
alls.erase(unique(alls.begin() ,alls.end() ), alls.end());
cout<<alls.size()<<endl;
for(auto c:alls)
cout<<c<<" ";
}