Submission #420128

#	Time	Username	Problem	Language	Result	Execution time	Memory
420128		Aldas25	Horses (IOI15_horses)	C++14	54 / 100	143 ms	29512 KiB

horses

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

using namespace std;

#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr)
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define REP(n) FOR(O, 1, (n))
#define f first
#define s second
#define pb push_back
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<ll> vl;

const int MAXN = 500100;
const ll MOD = 1e9+7;

ll pwr (ll a, ll p) {
    if (p == 0) return 1;
    if (p == 1) return a%MOD;
    ll ret = pwr(a, p/2);
    ret = (ret*ret)%MOD;
    if (p%2 == 1) ret = (ret*(a%MOD))%MOD;
    return ret%MOD;
}
ll modInv (ll a) {
    return pwr(a%MOD, MOD-2);
}

ll fen[MAXN];

void upd (int p, ll x) {
    for (int i = p; i < MAXN; i += i&(-i))
        fen[i] = (fen[i]*x)%MOD;
}

ll prefX (int p) {
    ll ret = 1;
    for (int i = p; i > 0; i -= i&(-i))
        ret = (ret * fen[i])%MOD;
    return ret;
}

int n;
ll x[MAXN], y[MAXN];

ll getMax () {
    int id = 1;
    if (n > 1000) id = max(1, n-40);

    ll cr = 1;
    FOR(i, id+1, n) {
        cr *= x[i];
        if (cr * y[i] > y[id]) {
            id = i;
            cr = 1;
        }
    }

    ll ret = (prefX(id) * y[id])%MOD;
    return ret;
}

int init(int N, int X[], int Y[]) {
    n = N;
    FOR(i, 1, n) x[i] = X[i-1];
    FOR(i, 1, n) y[i] = Y[i-1];
    FOR(i, 0, MAXN-1) fen[i] = 1;
    FOR(i, 1, n) upd (i, x[i]);

	return getMax();
}

int updateX(int pos, int val) {
    pos++;
    upd (pos, modInv(x[pos]));
    x[pos] = val;
    upd (pos, x[pos]);
	return getMax();
}

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

Compilation message (stderr)

horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:74:15: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   74 |  return getMax();
      |         ~~~~~~^~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:82:15: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   82 |  return getMax();
      |         ~~~~~~^~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:88:15: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   88 |  return getMax();
      |         ~~~~~~^~

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