Submission #955700

#	Time	Username	Problem	Language	Result	Execution time	Memory
955700		emad234	Horses (IOI15_horses)	C++17	20 / 100	1594 ms	48376 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define pii pair<ll, ll>
const ll mod = 1e9 + 7;
const ll mxN = 5e5 + 5;
using namespace std;
ll NN;
struct tree
{
	vector<pii> seg;
	ll s, e;
	void init(ll n)
	{
		NN = exp2(ceil(log2(n)));
		seg.resize(NN * 4);
	}
	ll queryMax(ll l = 1, ll r = NN, ll ind = 1)
	{
		if (l > e || r < s)
			return 0;
		if (l >= s && r <= e)
			return seg[ind].F;
		ll md = (l + r) / 2;
		return max(queryMax(l, md, ind * 2), queryMax(md + 1, r, ind * 2 + 1));
	}
	ll queryProd(ll l = 1, ll r = NN, ll ind = 1)
	{
		if (l > e || r < s)
			return 1;
		if (l >= s && r <= e)
			return seg[ind].S;
		ll md = (l + r) / 2;
		return (queryProd(l, md, ind * 2) * queryProd(md + 1, r, ind * 2 + 1)) % mod;
	}
	void update(pii val, ll ind)
	{
		ind += NN;
		seg[ind] = val;
		while (ind /= 2)
		{
			seg[ind].F = max(seg[ind * 2].F, seg[ind * 2 + 1].F);
			seg[ind].S = (seg[ind * 2].S * seg[ind * 2 + 1].S) % mod;
		}
	}
} seg;
struct ones
{
	ll l, r;
	friend bool operator<(ones a, ones b)
	{
		return a.l < b.l;
	}
};
set<ones> s;
ll st[mxN],ed[mxN];
ll x[mxN], y[mxN];
ll vals[mxN];
ll n;
ll solve()
{
	ll id = 0;
	int i = n - 1;
	while (i > 0 && id <= 70)
	{
		if (x[i] == 1)
		{
			i = st[i];
			id--;
		}
		i--;
		id++;
	}
	if(i == -1) i = 0;
	ll mx = -1, mxid = -1;
	ll prd = 1;
	for (i; i < n; i++)
	{
		if (x[i] == 1)
		{
			seg.s = i + 1, seg.e = ed[i] + 1;
			if (vals[i] * prd > mx)
			{
				mx = vals[i];
				mxid = i;
				prd = 1;
			}
			i = ed[i];
			continue;
		}
		if (prd * x[i] > mx)
		{
			mx = y[i];
			mxid = i;
			prd = 1;
			continue;
		}
		prd *= x[i];
		if (prd * y[i] > mx)
		{
			mx = y[i];
			mxid = i;
			prd = 1;
			continue;
		}
	}
	seg.s = 1;
	seg.e = mxid + 1;
	return (mx * seg.queryProd()) % mod;
}
int init(int N, int X[], int Y[])
{
	seg.init(N);
	n = N;
	for (ll i = 0; i < N; i++)
	{
		y[i] = Y[i];
		x[i] = X[i];
		seg.update({Y[i], X[i]}, i);
	}
	ll l = -1, r = -1;
	for (ll i = 0; i < N; i++)
	{
		if (X[i] == 1)
		{
			if (l == -1)
				l = i;
			r = i;
		}
		else
		{
			if (l != -1)
			{
				s.insert({l, r});
				l = r = -1;
			}
		}
	}
	if (l != -1)
	{
		s.insert({l, r});
		l = r = -1;
	}
	return solve();
}

int updateX(int pos, int val)
{
	if (x[pos] != 1 && val == 1)
	{
		auto it = s.upper_bound({pos, pos});
		ll l = pos, r = pos;
		if (it != s.end() && (*it).l == pos + 1)
		{
			l = pos, r = (*it).r;
			s.erase(it);
		}
		s.insert({l, r});
		it = s.lower_bound({pos, pos});
		auto p = s.lower_bound({l, r});
		if (it != s.begin())
		{
			it--;
			if ((*it).r == l - 1)
			{
				l = (*it).l;
				s.erase(it);
				s.erase(s.lower_bound({pos, pos}));
				s.insert({l, r});
			}
		}
		st[r] = l;
		ed[l] = r;
		seg.s = l + 1,seg.e = r + 1;
		vals[l] = seg.queryMax();
	}
	if (x[pos] == 1 && val != 1)
	{
		auto it = s.upper_bound({pos, 0});
		it--;
		ll l = (*it).l, r = pos - 1, l1 = pos + 1, r1 = (*it).r;
		s.erase(it);
		if (l <= r){
			s.insert({l, r});
			st[r] = l;
			ed[l] = r;
			seg.s = l + 1, seg.e = r + 1;
			vals[l] = seg.queryMax();
		}
		if (l1 <= r1){
			s.insert({l1, r1});
			st[r1] = l1;
			ed[l1] = r1;
			seg.s = l1 + 1, seg.e = r1 + 1;
			vals[l1] = seg.queryMax();
		}
	}
	x[pos] = val;
	seg.update({y[pos], x[pos]}, pos);
	return solve();
}

int updateY(int pos, int val)
{
	y[pos] = val;
	seg.update({y[pos], x[pos]}, pos);
	return solve();
}

Compilation message (stderr)

horses.cpp: In member function 'void tree::init(long long int)':
horses.cpp:18:12: warning: conversion from 'double' to 'long long int' may change value [-Wfloat-conversion]
   18 |   NN = exp2(ceil(log2(n)));
      |        ~~~~^~~~~~~~~~~~~~~
horses.cpp: In function 'long long int solve()':
horses.cpp:66:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   66 |  int i = n - 1;
      |          ~~^~~
horses.cpp:71:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   71 |    i = st[i];
      |        ~~~~^
horses.cpp:80:7: warning: statement has no effect [-Wunused-value]
   80 |  for (i; i < n; i++)
      |       ^
horses.cpp:91:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   91 |    i = ed[i];
      |        ~~~~^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:147:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  147 |  return solve();
      |         ~~~~~^~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:163:8: warning: variable 'p' set but not used [-Wunused-but-set-variable]
  163 |   auto p = s.lower_bound({l, r});
      |        ^
horses.cpp:203:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  203 |  return solve();
      |         ~~~~~^~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:210:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  210 |  return solve();
      |         ~~~~~^~

• Subtask 1: 0 / 17
• Subtask 2: 0 / 17
• Subtask 3: 20 / 20
• Subtask 4: 0 / 23
• Subtask 5: 0 / 23