【YCOJ 1059】最长上升子序列

#include<cstdio>
#include<iostream>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
typedef long long ll;
using namespace std;
const ll N=500002;
const ll oo=10000000000000000;
ll op[N],f[N],head[N];
ll a[N];
int ans[N];
struct node{
    ll next;
    ll to;
}e[N];
ll cnt,n;
void add(ll u,ll v){
    cnt++; e[cnt].to=v;
    e[cnt].next=head[u]; head[u]=cnt;
}

void dfs(ll  now){
    if(op[now]==1){
        ans[now]=lower_bound(f,f+1+n,oo)-(f+1);
        for(ll i=head[now];i;i=e[i].next)
            dfs(e[i].to);
    } 
    if(op[now]==0){
        ll ps=lower_bound(f,f+1+n,a[now])-f;
        ll tmp=f[ps]; f[ps]=a[now];
        ans[now]=lower_bound(f,f+1+n,oo)-(f+1);
        for(ll i=head[now];i;i=e[i].next)
            dfs(e[i].to);
        f[ps]=tmp;
    }
}

int main(){
    freopen("1059.in","r",stdin);
    freopen("1059.out","w",stdout);
    cin>>n;
    for(ll i=1;i<=n;i++){
        cin>>op[i]>>a[i];
        if(op[i]==1) add(a[i],i);
        else add(i-1,i);
    }
    op[0]=1;
    for(ll i=1;i<=n;i++) f[i]=oo; dfs(0);
    for(ll i=1;i<=n;i++)
        printf("%d\n",ans[i]);
    return 0;
}