Submission #431654

#	Time	Username	Problem	Language	Result	Execution time	Memory
431654		arayi	Horses (IOI15_horses)	C++17	17 / 100	1571 ms	51936 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define lli long long
using namespace std;

const int N = 5e5 + 30;
const lli mod = 1e9 + 7;


int n;
lli x[N], y[N];
lli t[4*N], t1[4*N];
set <int> fp;
void upd(int q, lli v, int l = 0, int r = n - 1, int nd = 1)
{
	if(q > r || q < l) return;
	if(l == r)
	{
		t[nd] = v;
		return;
	}
	int md = (l + r) / 2;
	upd(q, v, l, md, nd * 2); 
	upd(q, v, md + 1, r, nd * 2 + 1);
	t[nd] = max(t[nd*2], t[nd*2+1]);
}
lli qry(int l, int r, int nl = 0, int nr = n - 1, int nd = 1)
{
	if(l > nr || r < nl) return 0;
	if(nl==l&&r==nr) return t[nd];
	int md = (nl + nr)/2;
	return max(qry(l, min(md, r), nl, md, nd*2), qry(max(md + 1, l), r, md + 1, nr, nd * 2 + 1));
}
void upd1(int q, lli v, int l = 0, int r = n - 1, int nd = 1)
{
	if(q > r || q < l) return;
	if(l == r)
	{
		t1[nd] = v;
		return;
	}
	int md = (l + r) / 2;
	upd1(q, v, l, md, nd * 2); 
	upd1(q, v, md + 1, r, nd * 2 + 1);
	t1[nd] = (t1[nd*2] * t[nd*2+1]) % mod;
}
lli qry1(int l, int r, int nl = 0, int nr = n - 1, int nd = 1)
{
	if(l > nr || r < nl) return 1;
	if(nl==l&&r==nr) return t1[nd];
	int md = (nl + nr)/2;
	return (qry1(l, min(md, r), nl, md, nd*2) * qry1(max(md + 1, l), r, md + 1, nr, nd * 2 + 1))%mod;
}
lli slv()
{
	auto i1 = fp.end();
	int nx = n - 1;
	lli mx = 0;
	do
	{
		--i1;
		//cout << *i1 << "<-" << endl;
		mx = max(mx, qry(*i1, nx));
		mx *= x[*i1];
		nx = (*i1) - 1;
		//if(mx > mod) break;
	} while (i1 != fp.begin());
	mx %= mod;
	//cout << "SM" << endl;
	return (mx * qry1(0, nx))%mod;
}
int init(int N, int X[], int Y[]) 
{
	n = N;
	fp.insert(0);
	for (int i = 0; i < n; i++)
	{
		x[i]=X[i], y[i]=Y[i];
		if(x[i] > 1) fp.insert(i);
		upd(i, y[i]);
		upd1(i, x[i]);
	}	
	//cout << "SM" << endl;
	return slv();
}

int updateX(int pos, int val)
{	
	if(x[pos] > 1 && pos) fp.erase(pos);
	x[pos] = val;
	if(x[pos] > 1) fp.insert(pos);
	upd1(pos, val);
	return slv();
}

int updateY(int pos, int val) 
{
	y[pos] = val;
	upd(pos, val);
	return slv();
}

Compilation message (stderr)

horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:72:14: warning: declaration of 'N' shadows a global declaration [-Wshadow]
   72 | int init(int N, int X[], int Y[])
      |          ~~~~^
horses.cpp:6:11: note: shadowed declaration is here
    6 | const int N = 5e5 + 30;
      |           ^
horses.cpp:84:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   84 |  return slv();
      |         ~~~^~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:93:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   93 |  return slv();
      |         ~~~^~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:100:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  100 |  return slv();
      |         ~~~^~

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