重铸华农荣光 我辈义不容辞

the sixth day-double pointer-longest continuous non-repeating substring

#include<iostream>
using namespace std;
const int N=100010;
int a[N],s[N];
int n,ans;

int main()
{
    cin>>n;
    for(int i=0;i<n;i++) cin>>a[i];

    for(int i=0,j=0;i<n;i++){
        s[a[i]]++;
        while(s[a[i]]>1){
            s[a[j]]--;
            j++;
        }
        ans=max(ans,i-j+1);
    }

    cout<<ans;

    return 0;
}