欢乐水题,新年快乐朋友们!
#include <iostream>
using namespace std;
int main()
{
int a[1005] = {0};
int n;
scanf("%d",&n);
for(int i=0;i<n;i++)
{
int x;
scanf("%d",&x);
a[x] = 1;
}
int ans[n],top = 0;
for(int i=1;i<=1000;i++)
if(a[i])
ans[top++] = i;
cout<<top<<endl;
for(int i=0;i<top;i++)
printf("%d%c",ans[i]," \n"[i==top-1]);
return 0;
}