Submission #438478

#	Time	Username	Problem	Language	Result	Execution time	Memory
438478		adamjinwei	Horses (IOI15_horses)	C++14	17 / 100	537 ms	29372 KiB

horses

#include <bits/stdc++.h>
#include "horses.h"
#define lson (p<<1)
#define rson (p<<1|1)
#define inf 1000000007
#define mod 1000000007
#define rnd() rand_num()
#define bigrnd() dis(rand_num)
//#pragma GCC optimize("Ofast","inline","-ffast-math")
//#pragma GCC target("avx,sse2,sse3,sse4,mmx")
//#define int long long
using namespace std;
unsigned sed=std::chrono::system_clock::now().time_since_epoch().count();
mt19937 rand_num(sed);
uniform_int_distribution<long long> dis(0,inf);
template <typename T> void read(T &x){
	x=0;char ch=getchar();int fh=1;
	while (ch<'0'||ch>'9'){if (ch=='-')fh=-1;ch=getchar();}
	while (ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
	x*=fh;
}
template <typename T> void write(T x) {
	if (x<0) x=-x,putchar('-');
	if (x>9) write(x/10);
	putchar(x%10+'0');
}
template <typename T> void writeln(T x) {
	write(x);
	puts("");
}
int n;
long long x[500005],y[500005];
long long mx[2000005],tag[2000005];
long long qpow(long long a,long long b)
{
	long long res=1;
	while(b)
	{
		if(b&1) res=res*a%mod;
		a=a*a%mod;
		b>>=1;
	}
	return res;
}
void pushup(int p)
{
	mx[p]=max(mx[lson],mx[rson]);
}
void build(int p,int l,int r)
{
	if(l==r)
	{
		mx[p]=1;
		tag[p]=1;
		return;
	}
	tag[p]=1;
	int mid=l+r>>1;
	build(lson,l,mid);
	build(rson,mid+1,r);
	pushup(p);
}
void pushdown(int p)
{
	mx[lson]*=tag[p];
	mx[lson]%=mod;
	tag[lson]*=tag[p];
	tag[lson]%=mod;
	mx[rson]*=tag[p];
	mx[rson]%=mod;
	tag[rson]*=tag[p];
	tag[rson]%=mod;
	tag[p]=1;
}
void modify(int p,int l,int r,int x,int y,long long k)
{
	if(x<=l&&r<=y)
	{
		mx[p]*=k;
		mx[p]%=mod;
		tag[p]*=k;
		tag[p]%=mod;
		return;
	}
	int mid=l+r>>1;
	pushdown(p);
	if(x<=mid) modify(lson,l,mid,x,y,k);
	if(mid+1<=y) modify(rson,mid+1,r,x,y,k);
	pushup(p);
}
int init(int N,int X[],int Y[])
{
	n=N;
	for(int i=1;i<=n;++i)
	{
		x[i]=X[i-1];
		y[i]=Y[i-1];
	}
	build(1,1,n);
	for(int i=1;i<=n;++i)
	{
		modify(1,1,n,i,n,x[i]);
		modify(1,1,n,i,i,y[i]);
	}
	return mx[1]%mod;
}
int updateX(int pos,int val)
{
	pos++;
	modify(1,1,n,pos,n,qpow(x[pos],mod-2));
	modify(1,1,n,pos,n,val);
	x[pos]=val;
	return mx[1]%mod;
}
int updateY(int pos,int val)
{
	pos++;
	modify(1,1,n,pos,pos,qpow(y[pos],mod-2));
	modify(1,1,n,pos,pos,val);
	y[pos]=val;
	return mx[1]%mod;
}

Compilation message (stderr)

horses.cpp:13:71: warning: conversion from 'std::chrono::duration<long int, std::ratio<1, 1000000000> >::rep' {aka 'long int'} to 'unsigned int' may change value [-Wconversion]
   13 | unsigned sed=std::chrono::system_clock::now().time_since_epoch().count();
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
horses.cpp: In function 'void build(int, int, int)':
horses.cpp:58:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   58 |  int mid=l+r>>1;
      |          ~^~
horses.cpp: In function 'void modify(int, int, int, int, int, long long int)':
horses.cpp:75:41: warning: declaration of 'y' shadows a global declaration [-Wshadow]
   75 | void modify(int p,int l,int r,int x,int y,long long k)
      |                                     ~~~~^
horses.cpp:32:21: note: shadowed declaration is here
   32 | long long x[500005],y[500005];
      |                     ^
horses.cpp:75:35: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   75 | void modify(int p,int l,int r,int x,int y,long long k)
      |                               ~~~~^
horses.cpp:32:11: note: shadowed declaration is here
   32 | long long x[500005],y[500005];
      |           ^
horses.cpp:85:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   85 |  int mid=l+r>>1;
      |          ~^~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:105:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  105 |  return mx[1]%mod;
      |              ^
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:113:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  113 |  return mx[1]%mod;
      |              ^
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:121:14: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  121 |  return mx[1]%mod;
      |              ^

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