Submission #87445

#	Time	Username	Problem	Language	Result	Execution time	Memory
87445		JustasZ	Horses (IOI15_horses)	C++14	0 / 100	497 ms	41388 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define pb push_back
#define all(a) a.begin(), a.end()
#define sz(a) (int)a.size()
#define x first
#define y second
#define debug(...) "["<<#__VA_ARGS__<<": "<<__VA_ARGS__<<"]"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int>pii;
const int maxn=5e5+100;
const int mod=1e9+7;
const ld eps=1e-6;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll pwr(ll a, ll pw)
{
    ll ret=1;
    while(pw>0)
    {
        if(pw&1)ret=ret*a%mod;
        a=a*a%mod;
        pw>>=1;
    }
    return ret;
}
ll modinv(ll a)
{
    return pwr(a, mod-2);
}
int N;
ll X[maxn], Y[maxn];
ld seg[maxn*4], Xpref[maxn], lazy[maxn*4];
void build(int id=1, int l=0, int r=N-1)
{
    if(l == r)
    {
        seg[id]=Xpref[l]+log2((ld)Y[l]);
        return;
    }
    int mid=(l+r)/2;
    build(id*2, l, mid);
    build(id*2+1, mid+1, r);
    seg[id]=max(seg[id*2], seg[id*2+1]);
}
void laz(int id, ld d)
{
    seg[id]+=d;
    lazy[id]+=d;
}
void shift(int id)
{
    if(lazy[id])
    {
        laz(id*2, lazy[id]);
        laz(id*2+1, lazy[id]);
        lazy[id]=0;
    }
}
void modify(int x, int y, ld d, int id=1, int l=0, int r=N-1)
{
    if(l > y || r < x)return;
    if(l >= x && r <= y)
    {
        laz(id, d);
        return;
    }
    shift(id);
    int mid=(l+r)/2;
    modify(x, y, d, id*2, l, mid);
    modify(x, y, d, id*2+1, mid+1, r);
    seg[id]=max(seg[id*2], seg[id*2+1]);
}
int query(int x, int y, int id=1, int l=0, int r=N-1)
{
    if(l > y || r < x)return 0;
    if(l >= x && r <= y)return seg[id];
    shift(id);
    int mid=(l+r)/2;
    return max(query(x, y, id*2, l, mid), query(x, y, id*2+1, mid+1, r));
}

ll F[maxn];
void upd(int p, ll val)
{
    for(; p<=N; p+=p&-p)
        F[p]=(F[p]*val)%mod;
}
ll get(int p)
{
    ll ret=1;
    for(; p>0; p-=p&-p)
        ret=(ret*F[p])%mod;
    return ret;
}
int getans()
{
    int l=0, r=N-1;
    ld mx=query(0, N-1);
    while(l < r)
    {
        int mid=(l+r)/2;
        if(fabs(query(l, mid)-mx) < eps)r=mid;
        else l=mid+1;
    }
    //cout<<debug(l)<<"\n";
    return (int)(get(l+1)*Y[l]%mod);
}
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];
    for(int i=0; i<N; i++)
    {
        ld v=X[i];
        F[i+1]=1;
        Xpref[i]=log2(v);
        if(i > 0)Xpref[i]+=Xpref[i-1];
    }
    for(int i=1; i<=N; i++)
        upd(i, X[i-1]);
    build();
    return getans();
}
int updateX(int p, int val)
{
    ld d=log2((ld)val)-log2((ld)X[p]);
    ll up=modinv(X[p])*(ll)val%mod;
    X[p]=val;
    modify(0, p, d);
    upd(p+1, up);
    return getans();
}
int updateY(int p, int val)
{
    ld d=log2((ld)val)-log2((ld)Y[p]);
    Y[p]=val;
    modify(p, p, d);
    return getans();
}
/*int main()
{
    ios_base::sync_with_stdio(false), cin.tie(0);
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    int n, A[maxn], B[maxn];
    cin>>n;
    for(int i=0; i<n; i++)
        cin>>A[i];
    for(int i=0; i<n; i++)
        cin>>B[i];
    cout<<init(n, A, B)<<"\n";
    int m;
    cin>>m;
    while(m--)
    {
        int a, b, c;
        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 query(int, int, int, int, int)':
horses.cpp:78:38: warning: conversion to 'int' from 'ld {aka long double}' may alter its value [-Wfloat-conversion]
     if(l >= x && r <= y)return seg[id];
                                ~~~~~~^

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