Submission #754906

#	Time	Username	Problem	Language	Result	Execution time	Memory
754906		APROHACK	Horses (IOI15_horses)	C++14	54 / 100	1577 ms	29760 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;

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];
	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]);
	}
	updateRet();
	return maxV%mod;
}

int updateX(int pos, int val) {	
	multiplicar(pos + 1, fastExp(x[pos], mod-2));
	x[pos] = val;
	multiplicar(pos + 1, x[pos]);
	updateRet();
	return maxV%mod;
}

int updateY(int pos, int val) {
	y[pos] = val;
	updateRet();
	return maxV%mod;
}

Compilation message (stderr)

horses.cpp: In function 'void updateRet()':
horses.cpp:39:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   39 |   if(current > 1e9){
      |      ^~~~~~~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:61:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   61 |  return maxV%mod;
      |         ~~~~^~~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:65:30: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   65 |  multiplicar(pos + 1, fastExp(x[pos], mod-2));
      |                       ~~~~~~~^~~~~~~~~~~~~~~
horses.cpp:67:29: 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]
   67 |  multiplicar(pos + 1, x[pos]);
      |                             ^
horses.cpp:69:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   69 |  return maxV%mod;
      |         ~~~~^~~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:75:13: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   75 |  return maxV%mod;
      |         ~~~~^~~~

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