Submission #116947

#	Time	Username	Problem	Language	Result	Execution time	Memory
116947		someone_aa	Horses (IOI15_horses)	C++17	34 / 100	60 ms	14840 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int maxn = 501000;
const ll mod = 1e9 + 7;
ll x[maxn], y[maxn], n;

int solve() {
    if(n <= 1000) {
        ll result = (1LL * x[0] * y[0])%mod;
        ll prod = 1LL;
        ll pref = x[0];
        ll ind = 0;
        for(int i=1;i<n;i++) {
            prod *= x[i];
            ll curr = prod * y[i];
            pref *= x[i]; pref %= mod;
            if(curr >= y[ind]) {
                // buy this one
                result = (pref * y[i])%mod;
                prod = 1LL;
                ind = i;
            }
        }
        return result%mod;
    }
    else {
        ll result = (1LL * x[n-40] * y[n-40])%mod;
        ll prod = 1LL;
        ll pref = x[n-40];
        ll ind = 0;
        for(int i=n-39;i<n;i++) {
            prod *= x[i];
            ll curr = prod * y[i];
            pref *= x[i]; pref %= mod;
            if(curr >= y[ind]) {
                // buy this one
                result = (pref * y[i])%mod;
                prod = 1LL;
                ind = i;
            }
        }
        return result%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];
    }
    return solve();
}

int updateX(int pos, int val) {
	x[pos] = val;
	return solve();
}

int updateY(int pos, int val) {
	y[pos] = val;
	return solve();
}

Compilation message (stderr)

horses.cpp: In function 'int solve()':
horses.cpp:26:22: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         return result%mod;
                ~~~~~~^~~~
horses.cpp:33:20: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         for(int i=n-39;i<n;i++) {
                   ~^~~
horses.cpp:44:22: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
         return result%mod;
                ~~~~~~^~~~

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