Submission #641059

#	Time	Username	Problem	Language	Result	Execution time	Memory
641059		urosk	Exam (eJOI20_exam)	C++14	14 / 100	81 ms	616 KiB

exam

#define here cerr<<"===========================================\n"
#define dbg(x) cerr<<#x<<": "<<x<<endl;
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#define ld double
#define ll long long
#define llinf 100000000000000000LL // 10^17
#define pb push_back
#define popb pop_back
#define fi first
#define sc second
#define endl '\n'
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define sz(a) (ll)(a.size())
#define all(a) a.begin(),a.end()
#define ceri(a,l,r) {cerr<<#a<<": ";for(ll i_ = l;i_<=r;i_++) cerr<<a[i_]<< " ";cerr<<endl;}
#define daj_mi_malo_vremena ios_base::sync_with_stdio(false);cerr.tie(0);cout.tie(0);cin.tie(0);

using namespace std;
using namespace __gnu_pbds;
/*
ll add(ll x,ll y){
    x+=y;
    if(x<0){
        x%=mod;
        x+=mod;
    }else{
        if(x>=mod) x%=mod;
    }
    return x;
}
ll mul(ll a,ll b){
	ll ans = (a*b)%mod;
	if(ans<0) ans+=mod;
	return ans;
}
typedef tree<int,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<int,null_type,less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_multiset;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll rnd(ll l,ll r){
    return uniform_int_distribution<ll>(l,r)(rng);
}
*/
#define maxn 5005
ll n;
ll a[maxn],b[maxn],c[maxn],d[maxn];
pll p[maxn];
ll l[maxn],r[maxn];
ll t[4*maxn];
void upd(ll v,ll tl,ll tr,ll i,ll x){
    if(tl==tr){t[v] = x;return;}
    ll mid = (tl+tr)/2;
    if(i<=mid) upd(2*v,tl,mid,i,x);
    else upd(2*v+1,mid+1,tr,i,x);
    t[v] = t[2*v] + t[2*v+1];
}
void init(ll v,ll tl,ll tr){
    if(tl==tl){t[v] = (d[tl]==b[tl]);return;}
    ll mid = (tl+tr)/2;
    init(2*v,tl,mid); init(2*v+1,mid+1,tr);
    t[v] = t[2*v] + t[2*v+1];
}
ll ans,cur;
void upd(ll i,ll x){
    if(d[i]==b[i]) cur--;
    d[i] = x;
    if(d[i]==b[i]) cur++;
}
void tc(){
    cin >> n;
    for(ll i = 1;i<=n;i++) cin >> a[i];
    for(ll i = 1;i<=n;i++) cin >> b[i];
    for(ll i = 1;i<=n;i++) p[i] = {a[i],i};
    stack<ll> s;
    for(ll i = 1;i<=n;i++){
        while(sz(s)&&a[i]>=a[s.top()]) s.pop();
        if(!sz(s)) l[i] = 0;
        else l[i] = s.top();
        s.push(i);
    }
    while(sz(s)) s.pop();
    for(ll i = n;i>=1;i--){
        while(sz(s)&&a[i]>=a[s.top()]) s.pop();
        if(!sz(s)) r[i] = n+1;
        else r[i] = s.top();
        s.push(i);
    }
    sort(p+1,p+n+1);
    ans = 0;
    for(ll j = 1;j<=n;j++){
        ll x = p[j].fi;
        ll i = p[j].sc;
        ans = cur;
        upd(i,x);
        ll lmax = i,cntmax = cur;
        ll lgr = l[i];
        i--;
        while(i>lgr){
            upd(i,x);
            if(cur>cntmax) cntmax = cur,lmax = i;
            i--;
        }
        for(ll i = 1;i<=n;i++){
            if(i<=p[j].sc&&i>=lmax) upd(i,x);
            else upd(i,c[i]);
        }
        i = p[j].sc;
        ll rmax = i;
        cntmax = cur;
        ll rgr = r[i];
        i++;
        while(i<rgr){
            upd(i,x);
            if(cur>cntmax) cntmax = cur,rmax = i;
            i++;
        }
        for(ll i = 1;i<=n;i++){
            if(i<=rmax&&i>=lmax) upd(i,x);
            else upd(i,c[i]);
        }
        if(cur>ans){
            for(ll i = 1;i<=n;i++) c[i] = d[i];
        }else{
            for(ll i = 1;i<=n;i++) d[i] = c[i];
        }
    }
    cout<<cur<<endl;
}
int main(){
	daj_mi_malo_vremena
    int t; t = 1;
    while(t--){
        tc();
    }
	return 0;
}

Compilation message (stderr)

exam.cpp: In function 'void init(long long int, long long int, long long int)':
exam.cpp:60:10: warning: self-comparison always evaluates to true [-Wtautological-compare]
   60 |     if(tl==tl){t[v] = (d[tl]==b[tl]);return;}
      |        ~~^~~~

• Subtask 1: 14 / 14
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 23
• Subtask 5: 0 / 16
• Subtask 6: 0 / 22