Submission #262340

#	Time	Username	Problem	Language	Result	Execution time	Memory
262340		uacoder123	Horses (IOI15_horses)	C++14	17 / 100	260 ms	48248 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define FOR(i,a,b) for (auto i = (a); i <= (b); ++i)
#define NFOR(i,a,b) for(auto i = (a); i >= (b); --i)
#define all(x) (x).begin(), (x).end()
#define sz(x) lli(x.size())
#define mp(i,a) make_pair(i,a)
#define pb(a) push_back(a)
#define bit(x,b) (x&(1LL<<b))

typedef long long int lli;
typedef pair <lli,lli> ii;
typedef pair <lli,ii> iii;
typedef vector <lli> vi;

lli segt[2000001],lazy[2000001],arr1[5000001],arr2[500001];
lli n,mod=1000000007;
lli p(lli a)
{
  lli b=0,ans=1;
  while((1LL<<b)<=mod-2)
  {
    if(bit(mod-2,b))
      ans=(ans*a)%mod;
    a=(a*a)%mod;
    b++;
  }
  return ans;
}
void up(lli node,lli l,lli r,lli s,lli e,lli v)
{
  if(l>e||r<s)
    return;
  if(lazy[node]!=1)
  {
    segt[node]=(segt[node]*lazy[node])%mod;
    if(l!=r)
    {
      lazy[2*node+1]=(lazy[2*node+1]*lazy[node])%mod;
      lazy[2*node+2]=(lazy[2*node+2]*lazy[node])%mod;
    }
    lazy[node]=1;
  }
  if(l>=s&&r<=e)
  {
    segt[node]=(segt[node]*v)%mod;
    if(l!=r)
    {
      lazy[2*node+1]=(lazy[2*node+1]*v)%mod;
      lazy[2*node+2]=(lazy[2*node+2]*v)%mod;
    }
    return;
  }
  lli m=(l+r)/2;
  up(2*node+1,l,m,s,e,v);
  up(2*node+2,m+1,r,s,e,v);
  segt[node]=max(segt[2*node+1],segt[2*node+2]);
}
int init(int N, int X[], int Y[]) 
{
  for(lli i=0;i<=2000001;++i)
  {
    segt[i]=1;
    lazy[i]=1;
  }
  n=N;
  lli cur=(1);
  for(lli i=0;i<n;++i)
  {
    arr1[i]=X[i];
    arr2[i]=Y[i];
    cur=(cur*X[i]);
    up(0,0,n-1,i,i,(cur*Y[i])%mod);
  }
  return segt[0];
}

int updateX(int pos, int val) 
{
  lli v=p(arr1[pos]);
  v=(v*val)%mod;
  arr1[pos]=v;
  up(0,0,n-1,pos,n-1,v);
  return segt[0];
}
int updateY(int pos, int val) 
{
  lli v=p(arr2[pos]);
  v=(v*val)%mod;
  arr2[pos]=v;
  up(0,0,n-1,pos,pos,v);
  return segt[0];
}

Compilation message (stderr)

horses.cpp: In function 'lli p(lli)':
horses.cpp:26:15: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   26 |     if(bit(mod-2,b))
      |            ~~~^~
horses.cpp:12:19: note: in definition of macro 'bit'
   12 | #define bit(x,b) (x&(1LL<<b))
      |                   ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:78:16: warning: conversion from 'lli' {aka 'long long int'} to 'int' may change value [-Wconversion]
   78 |   return segt[0];
      |          ~~~~~~^
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:87:16: warning: conversion from 'lli' {aka 'long long int'} to 'int' may change value [-Wconversion]
   87 |   return segt[0];
      |          ~~~~~~^
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:95:16: warning: conversion from 'lli' {aka 'long long int'} to 'int' may change value [-Wconversion]
   95 |   return segt[0];
      |          ~~~~~~^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:66:12: warning: iteration 2000001 invokes undefined behavior [-Waggressive-loop-optimizations]
   66 |     segt[i]=1;
      |     ~~~~~~~^~
horses.cpp:64:16: note: within this loop
   64 |   for(lli i=0;i<=2000001;++i)
      |               ~^~~~~~~~~

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