Submission #30846

#	Time	Username	Problem	Language	Result	Execution time	Memory
30846		inqr	Horses (IOI15_horses)	C++14	100 / 100	1113 ms	76264 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define rt insert
#define st first
#define nd second
#define ll long long
#define pii pair < int , int >
#define DB printf("debug\n");
#define umax( x , y ) x = max( x , (y) )
#define umin( x , y ) x = min( x , (y) )
#define all(x) x.begin() , x.end()
#define MAXN 500005
#define MOD (ll)1000000007
using namespace std;
int n;
ll x[MAXN],y[MAXN];
pair<double,ll> st[4*MAXN];
pair<double,ll> lz[4*MAXN];

pair<double,ll> merge(pair<double,ll> a,pair<double,ll> b){
	return {a.st+b.st,(a.nd*b.nd+MOD)%MOD};
}

void lz_upd(int l,int r,int stp){
	st[stp]=merge(st[stp],lz[stp]);
	if(l!=r){
		lz[stp*2]=merge(lz[stp*2],lz[stp]);
		lz[stp*2+1]=merge(lz[stp*2+1],lz[stp]);
	}
	lz[stp]={0,1};
}

void upd(int ul,int ur,double uv1,ll uv2,int l,int r,int stp){
	lz_upd(l,r,stp);
	if(ur<l||r<ul)return;
	if(ul<=l&&r<=ur){
		lz[stp]={uv1,uv2};
		lz_upd(l,r,stp);
		return;
	}
	int m=(l+r)/2;
	upd(ul,ur,uv1,uv2,l,m,stp*2);upd(ul,ur,uv1,uv2,m+1,r,stp*2+1);
	st[stp]=max(st[stp*2],st[stp*2+1]);
}

void build(int l,int r,int stp){
	if(l==r){
		st[stp]=lz[stp]={0,1};
		return;
	}
	st[stp]=lz[stp]={0,1};
	int m=(l+r)/2;
	build(l,m,stp*2);build(m+1,r,stp*2+1);
}
ll invert(ll base){
	ll res=1;
	ll exp=MOD-2;
	while(exp>0){
		if(exp&1){
			res*=base;
			res%=MOD;
		}
		base*=base;
		base%=MOD;
		exp/=2;
	}
	return res;
}
int init(int N, int X[], int Y[]) {
	n=N;
	for(int i=0;i<n;i++)x[i]=X[i],y[i]=Y[i];
	build(0,n-1,1);
	for(int i=0;i<n;i++){
		upd(i,n-1,(double)log2(x[i]),x[i],0,n-1,1);
		upd(i,i,(double)log2(y[i]),y[i],0,n-1,1);
	}
	return st[1].nd;
}
int updateX(int pos, int val){	
	upd(pos,n-1,-(double)log2(x[pos]),invert(x[pos]),0,n-1,1);
	x[pos]=val;
	upd(pos,n-1,(double)log2(x[pos]),x[pos],0,n-1,1);
	return st[1].nd;
}
int updateY(int pos, int val) {
	upd(pos,pos,-(double)log2(y[pos]),invert(y[pos]),0,n-1,1);
	y[pos]=val;
	upd(pos,pos,(double)log2(y[pos]),y[pos],0,n-1,1);
	return st[1].nd;
}

Compilation message (stderr)

horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:7:12: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
 #define nd second
            ^
horses.cpp:79:15: note: in expansion of macro 'nd'
  return st[1].nd;
               ^
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:7:12: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
 #define nd second
            ^
horses.cpp:85:15: note: in expansion of macro 'nd'
  return st[1].nd;
               ^
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:7:12: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
 #define nd second
            ^
horses.cpp:91:15: note: in expansion of macro 'nd'
  return st[1].nd;
               ^

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