Submission #204770

#	Time	Username	Problem	Language	Result	Execution time	Memory
204770		TAISA_	Horses (IOI15_horses)	C++14	17 / 100	152 ms	13944 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
int x[500000],y[500000],dat[1<<22];
int n;
const ll mod=1000000007LL;
struct segtree{
	int n;
	void build(int n_){
		n=1;
		while(n<n_)n<<=1;
		for(int i=0;i<2*n;i++)dat[i]=1;
	}
	void upd(int k,ll s){
		k+=n;
		dat[k]=s;
		k>>=1;
		while(k>0){
			dat[k]=dat[k<<1]*dat[k<<1|1]%mod;
			k>>=1;
		}
	}
	ll get(int a,int b,int k,int l,int r){
		if(b<=l||r<=a)return 1LL;
		if(a<=l&&r<=b)return dat[k];
		int m=(l+r)/2;
		return get(a,b,k<<1,l,m)*get(a,b,k<<1|1,m,r)%mod;
	}
	ll get(int a,int b){return get(a,b,1,0,n);}
} seg;
int calc(){
	ll id=n-1,t=x[n-1];
	for(int i=n-2;i>=0;i--){
		if(y[i]>t*y[id]){
			id=i;
			t=1;
		}
		t*=x[i];
		if(t>=mod){
			break;
		}
	} 
	return y[id]*seg.get(0,id+1)%mod;
}
int init(int N, int X[], int Y[]) {
	n=N;
	seg.build(n);
	for(int i=0;i<n;i++){
		x[i]=X[i];
		y[i]=Y[i];
		seg.upd(i,x[i]);
	}
	return calc();
}
int updateX(int pos, int val) {	
	x[pos]=val;
	seg.upd(pos,val);
	return calc();
}

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

Compilation message (stderr)

horses.cpp: In member function 'void segtree::upd(int, ll)':
horses.cpp:17:10: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
   dat[k]=s;
          ^
horses.cpp: In function 'int calc()':
horses.cpp:44:27: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
  return y[id]*seg.get(0,id+1)%mod;
                         ~~^~
horses.cpp:44:30: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
  return y[id]*seg.get(0,id+1)%mod;
         ~~~~~~~~~~~~~~~~~~~~~^~~~

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