Submission #345014

#	Time	Username	Problem	Language	Result	Execution time	Memory
345014		ogibogi2004	Horses (IOI15_horses)	C++14	0 / 100	373 ms	36808 KiB

horses

#include "horses.h"
#include<bits/stdc++.h>
using namespace std;
#define y1 da
#define y2 ne
#define ll long long
const int MAXN=5e6+6;
const ll MOD=1e9+7;
int x1[MAXN],y1[MAXN];
ll fastpow(ll x,ll p)
{
	ll m=1,ret=1;
	for(ll i=0;i<31;i++)
	{
		if(p&(1ll<<i))
		{
			ret*=m;
			ret%=MOD;
		}
		m*=m;m%=MOD;
	}
	return ret;
}
ll inverse(ll x)
{
	return fastpow(x,MOD-2);
}
set<int>notones;
//int treeX[4*MAXN];
int treeY[4*MAXN];
void updateY(int idx,int l,int r,int q,int val)
{
	if(l>q||r<q)return;
	if(l==r)
	{
		treeY[idx]=val;
		return;
	}
	int mid=(l+r)/2;
	if(mid>=q)updateY(idx*2,l,mid,q,val);
	else updateY(idx*2+1,mid+1,r,q,val);
	treeY[idx]=max(treeY[idx*2],treeY[idx*2+1]);
}
int n;
int queryY(int idx,int l,int r,int ql,int qr)
{
	if(l>qr)return 0;
	if(r<ql)return 0;
	if(l>=ql&&r<=qr)return treeY[idx];
	int mid=(l+r)/2;
	if(mid+1>qr)return queryY(idx*2,l,mid,ql,qr);
	if(mid<ql)return queryY(idx*2+1,mid+1,r,ql,qr);
	return max(queryY(idx*2,l,mid,ql,qr),queryY(idx*2+1,mid+1,r,ql,qr));
}
/*
void updateX(int idx,int l,int r,int q,int val)
{
	if(l>q||r<q)return;
	if(l==r)
	{
		treeX[idx]=val;
		return;
	}
	int mid=(l+r)/2;
	if(mid>=q)updateX(idx*2,l,mid,q,val);
	else updateX(idx*2+1,mid+1,r,q,val);
	treeX[idx]=((ll)treeX[idx*2]*treeX[idx*2+1])%MOD;
}
int queryX(int idx,int l,int r,int ql,int qr)
{
	if(l>qr)return 1;
	if(r<ql)return 1;
	if(l>=ql&&r<=qr)return treeX[idx];
	int mid=(l+r)/2;
	if(mid+1>qr)return queryX(idx*2,l,mid,ql,qr);
	if(mid<ql)return queryX(idx*2+1,mid+1,r,ql,qr);
	return ((ll)queryX(idx*2,l,mid,ql,qr)*queryX(idx*2+1,mid+1,r,ql,qr))%MOD;
}*/
ll prodall=1;
ll solve()
{
	if(notones.size()==0)
	{
		return queryY(1,0,n-1,0,n-1);
	}
	int last=n;
	auto it=notones.end();--it;
	ll d1=1;
	pair<ll,ll>ans;
	ans={-1,-1};
	ll y2,cnt=0;
	for(;;--it)
	{
		cnt++;
		ll y1=queryY(1,0,n-1,(*it),last-1);
		if(ans.first==-1)
		{
			y2=y1;
			ans.first=y1;
			ans.second=d1;
		}
		else if(ans.first*d1<y1*ans.second)
		{
			ans.first=y1;y2=y1;
			ans.second=d1;
		}
		if(it==notones.begin())break;
		last=(*it);d1=(ll)d1*x1[(*it)];
		//if(cnt>32)break;
		if(d1>(ll)1e9)break;
		if(d1>(ll)1e9*ans.second/ans.first)break;
	}
	/*it=notones.end();--it;
	last=n;
	for(;;--it)
	{
		--j;
		if(j==0)
		{
			//cout<<queryX(1,0,n-1,0,(*it))<<" "<<queryY(1,0,n-1,(*it),last-1)<<endl;
			return ((ll)queryX(1,0,n-1,0,(*it))*queryY(1,0,n-1,(*it),last-1))%MOD;
		}
		last=(*it);
	}*/
	ll f=prodall;
	f*=inverse(ans.second);
	f%=MOD;
	return (f*y2)%MOD;
	return 0;
}
int init(int N, int X[], int Y[]) {
	n=N;
	for(int i=0;i<N;++i)
	{
		x1[i]=X[i];
		y1[i]=Y[i];
		prodall*=x1[i];prodall%=MOD;
		if(X[i]>0)
		{
			notones.insert(i);
		}
		//updateX(1,0,N-1,i,X[i]);
	}
	for(int i=0;i<N;++i)
	{
		updateY(1,0,N-1,i,Y[i]);
	}
	return solve();
}

int updateX(int pos, int val) {	
	prodall*=inverse(x1[pos]);prodall%=MOD;
	x1[pos]=val;
	prodall*=x1[pos];prodall%=MOD;
	if(val==1)
	{
		notones.erase(pos);
	}
	else notones.insert(pos);
	//updateX(1,0,n-1,pos,x1[pos]);
	return solve();
}

int updateY(int pos, int val) {
	y1[pos]=val;
	updateY(1,0,n-1,pos,y1[pos]);
	return solve();
}

Compilation message (stderr)

horses.cpp: In function 'long long int fastpow(long long int, long long int)':
horses.cpp:10:15: warning: unused parameter 'x' [-Wunused-parameter]
   10 | ll fastpow(ll x,ll p)
      |               ^
horses.cpp: In function 'long long int solve()':
horses.cpp:4:12: warning: declaration of 'da' shadows a global declaration [-Wshadow]
    4 | #define y1 da
      |            ^~
horses.cpp:95:6: note: in expansion of macro 'y1'
   95 |   ll y1=queryY(1,0,n-1,(*it),last-1);
      |      ^~
horses.cpp:4:12: note: shadowed declaration is here
    4 | #define y1 da
      |            ^~
horses.cpp:9:14: note: in expansion of macro 'y1'
    9 | int x1[MAXN],y1[MAXN];
      |              ^~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:148:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  148 |  return solve();
      |         ~~~~~^~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:161:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  161 |  return solve();
      |         ~~~~~^~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:167:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  167 |  return solve();
      |         ~~~~~^~

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