1012友好城市
include [HTML_REMOVED]
include [HTML_REMOVED]
include [HTML_REMOVED]
using namespace std;
const int N = 5001;
int f[N];
typedef pair[HTML_REMOVED] PII;
int main()
{
int n;
cin>>n;
vector[HTML_REMOVED] as;
for(int i = 0;i<n;i++)
{
int l,r;
scanf(“%d %d”,&l,&r);
as.push_back({l,r});
}
sort(as.begin(),as.end());
for(int i = 0;i<n;i++) f[i] = 1;
for(int i = 1;i<n;i++)
for(int j =0;j<i;j++)
{
if (as[j].second<as[i].second)
{
f[i] = max(f[i],f[j]+1);
}
}
int res = -1;
for(int i = 0;i<n;i++)
if (f[i]>res) res = f[i];
cout<<res<<endl;
return 0;
}
qp