Codeforces Round #333 (Div. 2) B Approximating a Constant Range

//multiset 删除数是只删除一个，不会将相同的都删除
#include <cstring>
#include <iostream>
#include <set>
#include <algorithm>
using namespace std;
multiset<int>s;
int a[100005];
int main()
{
int n;
cin>>n;
for(int i=0;i<n;i++)
cin>>a[i];
int l=0,maxt=0;
for(int i=0;i<n;i++){
s.insert(a[i]);
while(*s.rbegin()-*s.begin()>1)
s.erase(s.find(a[l++]));
maxt=max(maxt,(int)s.size());
}
cout<<maxt<<endl;
}