题目链接：最长连续不重复子序列

#include <iostream>

using namespace std;

const int N = 100010;
int n;
int a[N], s[N];

int main ()
{
    cin >> n;
    for(int i = 0; i < n; i ++) cin >> a[i];
    
    int res = 0;
    for(int i = 0, j = 0; i < n; i++)
    {
        s[a[i]]++;
        while(s[a[i]] > 1)
        {
            s[a[j]]--;
            j++;
        }
        res = max(res, i - j + 1);
    }
    cout << res << endl;
    return 0;
}