Submission #621319

#	Time	Username	Problem	Language	Result	Execution time	Memory
621319		A_D	Horses (IOI15_horses)	C++14	17 / 100	1577 ms	54156 KiB

horses

#include "horses.h"

#include <bits/stdc++.h>

using namespace std;

const int N=1e6+100;
const long long MOD=1e9+7;
const long long L=32;
long long x[N];
long long y[N];
set<int> st;
int n;
vector<int> vec;
long long seg[4*N];
long long seg2[4*N];

void build(int p,int s,int e)
{
    if(s==e){
        seg[p]=y[s];
        seg2[p]=x[s];
        return;
    }
    int mid=(s+e)/2;
    build(p*2,s,mid);
    build(p*2+1,mid+1,e);
    seg[p]=max(seg[p*2],seg[p*2+1]);
    seg2[p]=(seg2[p*2]*seg2[p*2+1])%MOD;
}

void update(int p,int s,int e,int i,int val)
{
    if(s==e){
        seg[p]=val;
        return;
    }
    int mid=(s+e)/2;
    if(i<=mid){
        update(p*2,s,mid,i,val);
    }
    else{
        update(p*2+1,mid+1,e,i,val);
    }
    seg[p]=max(seg[p*2],seg[p*2+1]);
}

void update2(int p,int s,int e,int i,int val)
{
    if(s==e){
        seg2[p]=val;
        return;
    }
    int mid=(s+e)/2;
    if(i<=mid){
        update2(p*2,s,mid,i,val);
    }
    else{
        update2(p*2+1,mid+1,e,i,val);
    }
    seg2[p]=(seg2[p*2]*seg2[p*2+1])%MOD;
}



long long get(int p,int s,int e,int a,int b)
{
    if(a<=s&&e<=b){
        return seg[p];
    }
    if(s>b||e<a)return 1;
    int mid=(s+e)/2;
    return max(get(p*2,s,mid,a,b),get(p*2+1,mid+1,e,a,b));
}

long long get2(int p,int s,int e,int a,int b)
{
    if(b==-1)return 1;
    if(a<=s&&e<=b){
        return seg2[p];
    }
    if(s>b||e<a)return 1;
    int mid=(s+e)/2;
    return (get2(p*2,s,mid,a,b)*get2(p*2+1,mid+1,e,a,b))%MOD;
}

void filvec()
{
    vec.clear();
    int cnt=0;
    for(auto x:st){
        vec.push_back(-x);
        cnt++;
        if(cnt==L)continue;
    }
    if(vec.empty()||vec.back()!=0)vec.push_back(0);
    reverse(vec.begin(),vec.end());
}
long long getansst()
{
    filvec();
    long long ret=0;
    long long sum2=1,val=0;
    for(auto i:vec){
        sum2*=x[i];
        long long u=sum2*get(1,0,n-1,i,n-1);
        if(u>val){
            sum2=1;
            ret=((get(1,0,n-1,i,n-1))%MOD)*get2(1,0,n-1,0,i);
            val=y[i];
        }
    }
    ret%=MOD;
    return ret;
}



int init(int N, int X[], int Y[]){
    st.clear();
    n=N;
    for(int i=0;i<N;i++){
        x[i]=X[i];
        y[i]=Y[i];
        if(x[i]!=1){
            st.insert(-i);
        }
    }
    build(1,0,n-1);

    long long u=getansst();
    return u;
}

int updateX(int pos, int val) {

    if(x[pos]!=1)st.erase(-pos);
    x[pos]=val;
    if(x[pos]!=1)st.insert(-pos);

    update2(1,0,n-1,pos,val);

    long long u=getansst();
    return u;
}

int updateY(int pos, int val) {

    update(1,0,n-1,pos,val);


    long long u=getansst();
    return u;

}

Compilation message (stderr)

horses.cpp: In function 'void filvec()':
horses.cpp:91:14: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   91 |     for(auto x:st){
      |              ^
horses.cpp:10:11: note: shadowed declaration is here
   10 | long long x[N];
      |           ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:119:14: warning: declaration of 'N' shadows a global declaration [-Wshadow]
  119 | int init(int N, int X[], int Y[]){
      |          ~~~~^
horses.cpp:7:11: note: shadowed declaration is here
    7 | const int N=1e6+100;
      |           ^
horses.cpp:132:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  132 |     return u;
      |            ^
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:144:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  144 |     return u;
      |            ^
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:153:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  153 |     return u;
      |            ^

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