Submission #1213029

#	Time	Username	Problem	Language	Result	Execution time	Memory
1213029		Lemser	Horses (IOI15_horses)	C++20	100 / 100	520 ms	79672 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
using ull = unsigned long long;
using lld = long double;
using ii = pair<int,int>;
using pll = pair<ll, ll>;
 
using vi = vector<int>;
using vll = vector<ll>;
using vii = vector<ii>;
using vpll = vector<pll>;
using vlld = vector<lld>;
 
#define all(x) x.begin(),x.end()
#define lsb(x) x&(-x)
#define gcd(a,b) __gcd(a,b)
#define sz(x) (int)x.size()
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fls cout.flush()
 
#define fore(i, l, r) for (auto i = l; i < r; i++)
#define fo(i, n) fore (i, 0, n)
#define forex(i, r, l) for (auto i = r-1; i >= l; i--)
#define ffo(i, n) forex (i, n, 0)
 
bool cmin(ll &a, ll b) { if (b < a) { a=b; return 1; } return 0; }
bool cmax(ll &a, ll b) { if (b > a) { a=b; return 1; } return 0; }

const ll INF = 1e18;
const int N = 5e5 + 7, mod = 1e9 + 7;
int x[N], y[N], n;

struct SegTree {
    
    vll st;
    ll n;

    SegTree () {}
    SegTree (ll n):n(n), st(4*n+4, 1) {}

    void update(ll i, ll v){update(1,0,n-1,i,v);}
    void update(ll id,ll l,ll r,ll i,ll v){
        if(l==r)st[id] = v;
        else{
            ll m = (l+r)/2;
            if(i<=m) update(id*2,l,m,i,v);
            else update(id*2+1,m+1,r,i,v);
            st[id] = (st[id*2] * st[id*2+1])%mod;
        }
    }

    ll query(ll l,ll r){return query(1,0,n-1,l,r);}
    ll query(ll id,ll l,ll r,ll i,ll j){
        if(l>j || r<i)return 1;
        if(l>=i && r<=j)return st[id];
        ll m = (l+r)/2;
        return (query(id*2,l,m,i,j) * query(id*2+1,m+1,r,i,j))%mod;
    }

};

struct SegTreemx {
    
    vector<array<ll, 2>> st;
    ll n;

    SegTreemx () {}
    SegTreemx (ll n):n(n), st(4*n+4, array<ll, 2>{-INF, 0}) {}

    void update(ll i, array<ll, 2> v){update(1,0,n-1,i,v);}
    void update(ll id,ll l,ll r,ll i,array<ll, 2> v){
        if(l==r)st[id] = v;
        else{
            ll m = (l+r)/2;
            if(i<=m) update(id*2,l,m,i,v);
            else update(id*2+1,m+1,r,i,v);
            st[id] = max(st[id*2], st[id*2+1]);
        }
    }

    array<ll, 2> query(ll l,ll r){return query(1,0,n-1,l,r);}
	array<ll, 2> query(ll id,ll l,ll r,ll i,ll j){
        if(l>j || r<i)return {-INF, -INF};
        if(l>=i && r<=j)return st[id];
        ll m = (l+r)/2;
        return max(query(id*2,l,m,i,j), query(id*2+1,m+1,r,i,j));
    }

};

SegTree st;
SegTreemx sty;
set<ll> imps;

int calc () {
	map<int, array<ll, 2>> mx;
	ll suf = 1, ls = n-1;
	for (ll _: imps) {
		ll i = -_;
		mx[suf] = sty.query(i, ls);
		suf *= x[i];
		if (suf >= 1e9) break;
		ls = i - 1;
	}
	if (suf < 1e9) {
		mx[suf] = sty.query(0, ls);
	}
	if (imps.size() == 0) {
		return sty.query(0, n-1)[0];
	}
	// ffo (i, n-1) {
	// 	suf *= x[i+1];
	// 	if (suf >= 1e9) break;
	// 	mx[suf] = max(mx[suf], array<int, 2>{y[i], i});
	// }
	ll bst = n-1;
	suf = 1;
	for (auto [act_suf, v]: mx) {
		if (1ll*v[0] > 1ll*(act_suf/suf)*y[bst]) {
			bst = v[1];
			suf = act_suf;
		}
	}
	ll ans = st.query(0, bst);
	(ans *= y[bst]) %= mod;
	return int(ans);
}

void add (ll i) { if (x[i]>1) imps.insert(-i); }
void rem (ll i) { if (x[i]>1) imps.erase(-i); }

int init(int NN, int X[], int Y[]) {
	n = NN;
	st = SegTree(n);
	sty = SegTreemx(n);
	fo (i, n) {
		x[i] = X[i];
		y[i] = Y[i];
	}
	fo (i, n) st.update(i, x[i]);
	fo (i, n) sty.update(i, array<ll, 2> {y[i], i});
	fo (i, n) add(i);
	return calc();
}

int updateX(int pos, int val) {	
	rem(pos);
	x[pos] = val;
	add(pos);
	st.update(pos, val);
	return calc();
}

int updateY(int pos, int val) {
	sty.update(pos, array<ll, 2>{val, pos});
	y[pos] = val;
	return calc();
}

• Subtask 1: 17 / 17
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 23 / 23
• Subtask 5: 23 / 23