《最长连续不重复子序列》

#include <bits/stdc++.h>

using namespace std;

const int N = 100010;

int a[N], b[N];

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