Submission #767632

#	Time	Username	Problem	Language	Result	Execution time	Memory
767632		ThegeekKnight16	Horses (IOI15_horses)	C++17	100 / 100	175 ms	103944 KiB

horses

#include <bits/stdc++.h>
#include "horses.h"
using namespace std;
typedef long long ll;
const int MAXN = 5e5 + 10;
const ll MOD = 1e9 + 7;
ll X[MAXN], Y[MAXN];

inline ll mult(ll a, ll b) {return (a * b) % MOD;}
inline ll mult(ll a, ll b, ll c) {return (mult(a, b)*c) % MOD;}
ll exp(ll x, ll b)
{
	if (b == 0) return 1LL;
	if (b % 2) return mult(x, exp(x, b-1));
	else return exp(mult(x, x), b/2);
}

int N;
struct node
{
	ll prefX, sufX, y;
	bool bigPref;
	ll val;

	node (ll PX = 0, ll SX = 0, ll YY = 0, bool BIG = false) : prefX(PX), sufX(SX), y(YY), bigPref(BIG) {val = mult(prefX, y);}

	node operator+(node outro)
	{
		node resp;
		if (outro.y >= y || outro.bigPref || outro.prefX >= y || (sufX * outro.prefX) >= y || (sufX * outro.prefX * outro.y) >= y)
			resp = node( mult(prefX, sufX, outro.prefX), outro.sufX, outro.y, bigPref || outro.bigPref || (prefX * sufX) >= MOD || (prefX * sufX * outro.prefX) >= MOD );
		else resp = node(prefX, mult(sufX, outro.prefX, outro.sufX), y, bigPref);
		return resp;
	}
} seg[4*MAXN];

void build(int pos, int ini, int fim)
{
	if (ini == fim)
	{
		seg[pos] = node(X[ini], 1, Y[ini]);
		return;
	}
	int m = (ini + fim) >> 1;
	int e = 2*pos; int d = 2*pos + 1;
	build(e, ini,  m );
	build(d, m+1, fim);
	seg[pos] = seg[e] + seg[d];
}

void segUpdate(int pos, int ini, int fim, int id)
{
	if (id < ini || id > fim) return;
	if (ini == fim)
	{
		seg[pos] = node(X[ini], 1, Y[ini]);
		return;
	}
	int m = (ini + fim) >> 1;
	int e = 2*pos; int d = 2*pos + 1;
	segUpdate(e, ini,  m , id);
	segUpdate(d, m+1, fim, id);
	seg[pos] = seg[e] + seg[d];
}


int init(int _N, int _X[], int _Y[])
{
	N = _N;
	for (int i = 1; i <= N; i++) X[i] = _X[i-1], Y[i] = _Y[i-1];
	build(1, 1, N);

	return (int)seg[1].val;
}

int updateX(int id, int _val)
{
	++id;
	X[id] = _val;
	segUpdate(1, 1, N, id);
	return (int)seg[1].val;
}

int updateY(int id, int _val)
{
	++id;
	Y[id] = _val;
	segUpdate(1, 1, N, id);
	return (int)seg[1].val;
}

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