桶排

# include <bits/stdc++.h>
using namespace std;
int main(){
	int u,n,num=0,x;
	cin>>n;
	int a[1001]={0};
	for (u=1;u<=n;u++)
	{
		cin>>x;
		a[x]+=1;
		if (a[x]<=1)
		num+=1;
	}
	cout<<num<<endl;
	for (u=0;u<1001;u++)
		if (a[u]!=0)
		cout<<u<<" ";
	return 0;
}

请看题解

真的太6了

#include<bits/stdc++.h> using namespace std; int main() { int n,x; cin>>n; int sum(0),bus[1002]={0}; for(int i=1;i<=n;i++){ cin>>x; if(bus[x]) continue; bus[x]++; sum++; } cout<<sum<<endl; for(int i=1;i<=1000;i++) if(bus[i]) cout<<i<<' '; cout<<endl; return 0; }

6