排序

#include<iostream>
#include<algorithm>
using namespace std;
const int N = 1005;
int arr[N],num[N];
int main () {
    int n,i = 0,temp;
    cin >> n;
    for (int j = 1;j <= n;j++) {
        cin >> temp;
        if (num[temp] == 0) {
            num[temp]++;
            arr[i++] = temp;
        }
    }
    sort(arr,arr + i);
    cout << i << endl;
    for (int j = 0;j < i;j++) {
        cout << arr[j] << ' ';
    }
    return 0;
}