Submission #364950

#	Time	Username	Problem	Language	Result	Execution time	Memory
364950		BartolM	Horses (IOI15_horses)	C++17	17 / 100	79 ms	25452 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>

using namespace std;

#define X first
#define Y second
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;

const int INF=0x3f3f3f3f;
const int MOD=1e9+7;
const int OFF=(1<<19);
const int MAXN=5e5+5;

int n;
pii T[2*OFF];
int Tmax[2*OFF];
int x[MAXN], y[MAXN];

int mul(int a, int b) {
    return (ll)a*b%MOD;
}

pii mrg(pii a, pii b) {
    pii ret=mp(mul(a.X, b.X), a.Y || b.Y);
    ret.Y|=ret.X!=a.X*b.X;
    return ret;
}

int nadji(int pos=1) {
    if (pos>=OFF) return pos-OFF;
    if (T[pos*2+1].Y) return nadji(pos*2+1);
    return nadji(pos*2);
}

int query(int a, int b, int pos=1, int lo=0, int hi=OFF) {
    if (lo>=a && hi<=b) return T[pos].X;
    if (lo>=b || hi<=a) return 1;
    int mid=(lo+hi)/2;
    return mul(query(a, b, pos*2, lo, mid), query(a, b, pos*2+1, mid, hi));
}

int answer() {
    int ind=-1;
    if (T[1].Y) ind=nadji();
    ll ret=0, curr=1;
    for (int i=ind+1; i<n; ++i) {
        curr*=x[i];
        ret=max(ret, curr*y[i]);
    }
    return mul(ret%MOD, query(0, ind));
}

int init(int N, int XX[], int YY[]) {
    n=N;
    for (int i=0; i<n; ++i) x[i]=XX[i], y[i]=YY[i];

    fill(T, T+2*OFF, mp(1, 0));
    memset(Tmax, 0, sizeof Tmax);
    for (int i=0; i<n; ++i) T[OFF+i].X=x[i], Tmax[OFF+i]=y[i];
    for (int i=OFF-1; i>0; --i) T[i]=mrg(T[i*2], T[i*2+1]), Tmax[i]=max(Tmax[i*2], Tmax[i*2+1]);

    return answer();
}

int updateX(int pos, int val) {
    x[pos]=val;
    pos+=OFF;
    T[pos].X=val;
    pos/=2;
    while (pos) {
        T[pos]=mrg(T[pos*2], T[pos*2+1]);
        pos/=2;
    }
    return answer();
}

int updateY(int pos, int val) {
    y[pos]=val;
    pos+=OFF;
    Tmax[pos]=val;
    pos/=2;
    while (pos) {
        Tmax[pos]=max(Tmax[pos*2], Tmax[pos*2+1]);
        pos/=2;
    }
    return answer();
}

Compilation message (stderr)

horses.cpp: In function 'int mul(int, int)':
horses.cpp:27:19: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   27 |     return (ll)a*b%MOD;
      |            ~~~~~~~^~~~
horses.cpp: In function 'int answer()':
horses.cpp:57:19: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   57 |     return mul(ret%MOD, query(0, ind));
      |                ~~~^~~~

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