Submission #757882

#	Time	Username	Problem	Language	Result	Execution time	Memory
757882		APROHACK	Horses (IOI15_horses)	C++14	100 / 100	323 ms	37920 KiB

horses

#include <bits/stdc++.h>
#include "horses.h"
#define ll long long
#define pb push_back
const ll mod = 1e9+7;
using namespace std;
int n;
ll maxV = 0;
ll acum[500005];
vector<ll>x, y;
set<int>doses;

int maximos[500000*4], posiciones[500000*4];


void merge(int node){
	if(maximos[node*2] > maximos[node*2+1]){
		maximos[node] = maximos[node*2];
		posiciones[node] = posiciones[node*2];
	}else{
		maximos[node] = maximos[node*2+1];
		posiciones[node] = posiciones[node*2+1];
	}
}
void updateVal(int node, int l, int r, int pos, int value){
	int temp = (l+r)/2;
	if(l == r){
		maximos[node] = value;
		posiciones[node] = pos;
	}else if(pos <= temp){
		updateVal(node*2, l, temp, pos, value);
		merge(node);
	}else{
		updateVal(node*2+1, temp+1, r, pos, value);
		merge(node);
	}
}
int queryMaximo(int node, int l, int r, int dd, int ht){
	if(dd == l and ht == r)return posiciones[node];
	int temp = (l + r ) /2;
	if(ht <= temp)return queryMaximo(node*2, l, temp, dd, ht);
	else if(dd > temp)return queryMaximo(node*2+1, temp+1, r, dd, ht);
	else{
		int m1 = queryMaximo(node*2, l, temp, dd, temp), m2 = queryMaximo(node*2+1, temp+1, r, temp+1, ht);
		if(y[m1] > y[m2]){
			return m1;
		}else return m2;
	}
}
int qq(int node, int l, int r, int dd , int ht){
	if(dd > ht)return -1;
	if ( dd == ht )return dd;
	return queryMaximo(node, l, r, dd, ht);
}


ll fastExp(ll base, int pot){
	if(pot == 0)return 1;
	ll temp = fastExp(base, pot/2);
	temp = temp * temp % mod;
	if(pot % 2 == 1)temp = (temp * base) % mod;
	return temp;
}

ll query(int pos){
	ll ans = 1;
	for(; pos>= 1 ; pos -= (pos&-pos)){
		ans *= acum[pos];
		ans %= mod;
	}
	return ans;
}
void multiplicar(int pos , int value){
	for(; pos<= n ; pos += pos&(-pos)){
		acum[pos] *= value;
		acum[pos] %= mod;
	}
}

void updateRet(){
	ll ans = query(n) * y[n-1] % mod;
	ll current = x[n-1]* y[n-1];
	int curpos = n-1;
	int realI;
	for(auto i : doses){
		realI = -i;
		if(realI == n-1)continue;
		int mm = qq(1, 0, n-1, realI+1, curpos-1);
		if(mm != -1){
			if(y[mm] > current){
				ans = query(mm+1) * y[mm] % mod;
				current = x[mm]*y[mm];
			}
		}
		if(current > 1e9){
			maxV = ans;
			return ;
		}
		if(current < y[realI]){
			ans = query(realI+1) * y[realI] % mod;
			current = x[realI]*y[realI];
		}else{
			current = current * x[realI];
		}
		curpos = 	realI;
		if(current > 1e9){
			maxV = ans;
			return ;
		}
	}
	int mm = qq(1, 0, n-1, 0, curpos-1);
	if(mm != -1){
		if(y[mm] > current){
			ans = query(mm+1) * y[mm] % mod;
			current = x[mm]*y[mm];
		}
	}
	/*
	for(int i = n-2 ; i >= 0 ; i --){
		if(current > 1e9){
			maxV = ans;
			return ;
		}
		if(current < y[i]){
			ans = query(i+1) * y[i] % mod;
			current = x[i]*y[i];
		}else{
			current = current * x[i];
		}
	}
	*/
	maxV = ans;
}
int init(int N, int X[], int Y[]) {
	n = N;
	for(int i = 0 ; i <= n ; i ++)acum[i] = 1;
	for(int i = 0 ; i < N ; i++){
		x.pb(X[i]);
		y.pb(Y[i]);
		multiplicar(i+1, X[i]);
		updateVal(1, 0, N-1, i, Y[i]);
	}
	for(int i = n-1 ; i >=0 and doses.size() < 100 ; i --){
		if(x[i] > 1)doses.insert(-i);
	}
	updateRet();
	return maxV%mod;
}

int updateX(int pos, int val) {	
	multiplicar(pos + 1, fastExp(x[pos], mod-2));
	if(x[pos] > 1 and val == 1 and doses.find(-pos) != doses.end())doses.erase(-pos);
	else if(x[pos] == 1 and val > 1)doses.insert(-pos);
	if(doses.size()==100)doses.erase(prev(doses.end()));
	x[pos] = val;
	multiplicar(pos + 1, x[pos]);
	updateRet();
	return maxV%mod;
}

int updateY(int pos, int val) {
	y[pos] = val;
	updateVal(1, 0, n-1, pos, val);
	updateRet();
	return maxV%mod;
}

Compilation message (stderr)

horses.cpp: In function 'void updateRet()':
horses.cpp:95:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   95 |   if(current > 1e9){
      |      ^~~~~~~
horses.cpp:106:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  106 |   if(current > 1e9){
      |      ^~~~~~~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:147:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  147 |  return maxV%mod;
      |         ~~~~^~~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:151:30: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  151 |  multiplicar(pos + 1, fastExp(x[pos], mod-2));
      |                       ~~~~~~~^~~~~~~~~~~~~~~
horses.cpp:156:29: warning: conversion from '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} to 'int' may change value [-Wconversion]
  156 |  multiplicar(pos + 1, x[pos]);
      |                             ^
horses.cpp:158:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  158 |  return maxV%mod;
      |         ~~~~^~~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:165:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  165 |  return maxV%mod;
      |         ~~~~^~~~

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