Submission #422547

#	Time	Username	Problem	Language	Result	Execution time	Memory
422547		vanic	Horses (IOI15_horses)	C++14	17 / 100	216 ms	17256 KiB

horses

#include "horses.h"
#include <algorithm>
#include <cmath>
#include <iostream>

using namespace std;

typedef long long ll;

const int mod=1e9+7, Log=30, maxn=5e5, Log1=19, pot=(1<<Log1);

inline int sum(int a, int b){
	if(a+b>=mod){
		return a+b-mod;
	}
	if(a+b<0){
		return a+b+mod;
	}
	return a+b;
}

inline int mul(int a, int b){
	return (ll)a*b%mod;
}

inline int pote(int a, int b){
	int sol=1;
	for(int i=0; i<Log; i++){
		if((1<<i)&b){
			sol=mul(sol, a);
		}
		a=mul(a, a);
	}
	return sol;
}

inline int dij(int a, int b){
	return mul(a, pote(b, mod-2));
}

int t[pot*2];
int prop[pot*2];
int a[maxn];
int b[maxn];

void precompute(){
	for(int i=1; i<pot*2; i++){
		prop[i]=1;
		t[i]=1;
	}
}

void propagate(int x){
	if(prop[x]==1){
		return;
	}
	t[x]=mul(t[x], prop[x]);
	if(x<pot){
		prop[x*2]=mul(prop[x*2], prop[x]);
		prop[x*2+1]=mul(prop[x*2+1], prop[x]);
	}
	prop[x]=1;
}

void update(int L, int D, int x, int l, int d, int val){
	propagate(x);
	if(L>=l && D<=d){
		t[x]=mul(t[x], val);
		if(x<pot){
			prop[x*2]=mul(prop[x*2], val);
			prop[x*2+1]=mul(prop[x*2+1], val);
		}
		return;
	}
	if((L+D)/2>=l){
		update(L, (L+D)/2, x*2, l, d, val);
	}
	if((L+D)/2+1<=d){
		update((L+D)/2+1, D, x*2+1, l, d, val);
	}
	t[x]=max(t[x*2], t[x*2+1]);
}

int init(int n, int x[], int y[]){
	precompute();
	int val=1;
	for(int i=0; i<n; i++){
		a[i]=x[i];
		b[i]=y[i];
		val=mul(val, a[i]);
		update(0, pot-1, 1, i, i, mul(val, b[i]));
	}
	return t[1];
}

int updateX(int pos, int val) {	
	update(0, pot-1, 1, pos, pot-1, dij(val, a[pos]));
	a[pos]=val;
	return t[1];
}

int updateY(int pos, int val) {
	update(0, pot-1, 1, pos, pos, dij(val, b[pos]));
	b[pos]=val;
	return t[1];
}

/*
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin >> n;
	int x[n], y[n];
	for(int i=0; i<n; i++){
		cin >> x[i];
	}
	for(int i=0; i<n; i++){
		cin >> y[i];
	}
	cout << init(n, x, y) << '\n';
	int q;
	cin >> q;
	int a, b, c;
	for(int i=0; i<q; i++){
		cin >> a >> b >> c;
		if(a==1){
			cout << updateX(b, c) << '\n';
		}
		else{
			cout << updateY(b, c) << '\n';
		}
	}
	return 0;
}
*/

Compilation message (stderr)

horses.cpp: In function 'int mul(int, int)':
horses.cpp:23:16: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   23 |  return (ll)a*b%mod;
      |         ~~~~~~~^~~~

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