先sort，再unique int n = unique(a,a+n) - a; n為去重後陣列長度

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a[233];
    int n;
    cin >> n;
    for(int i=1;i<=n;i++)
        cin >> a[i];
    sort(a+1,a+1+n);
    int N = unique(a+1,a+1+n)-(a+1);
    for(int i=1;i<=N;
 
i++)
    cout << a[i] << " ";

    cout << endl << N <<endl;
    return 0;
}