제출 #778226

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
778226		danikoynov	말 (IOI15_horses)	C++14	54 / 100	1571 ms	27508 KiB

horses

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

using namespace std;
typedef long long ll;

const int maxn = 5e5 + 10;
const ll mod = 1e9 + 7;
ll x[maxn], y[maxn], n;

ll prod_tree[4 * maxn];

void build_prod_tree(int root, int left, int right)
{
    if (left == right)
    {
        prod_tree[root] = x[left];
        return;
    }

    int mid = (left + right) / 2;
    build_prod_tree(root * 2, left, mid);
    build_prod_tree(root * 2 + 1, mid + 1, right);

    prod_tree[root] = (prod_tree[root * 2] * prod_tree[root * 2 + 1]) % mod;
}

void update_prod(int root, int left, int right, int pos)
{
    if (left == right)
    {
        prod_tree[root] = x[left];
        return;
    }

    int mid = (left + right) / 2;
    if (pos <= mid)
        update_prod(root * 2, left, mid, pos);
    else
        update_prod(root * 2 + 1, mid + 1, right, pos);

    prod_tree[root] = (prod_tree[root * 2] * prod_tree[root * 2 + 1]) % mod;
}

ll prod_query(int root, int left, int right, int qleft, int qright)
{
    if (left > qright || right < qleft)
        return 1;
    if (left >= qleft && right <= qright)
        return prod_tree[root];

    int mid = (left + right) / 2;
    return (prod_query(root * 2, left, mid, qleft, qright) *
            prod_query(root * 2 + 1, mid + 1, right, qleft, qright)) % mod;
}

ll action()
{
    ll up = y[n - 1], dw = 1, pos = n - 1;
    ll div = 1;
    for (int i = n - 2; i >= 0; i --)
    {
        div = div * x[i + 1];
        if (div > 1e9)
            break;
            ///cout << i << " : " << y[i] << " " << div << endl;
        /// y[i] / div >? up / dw
        if (y[i] * dw >= up * div)
        {

            ///cout << " " << up << " : " << dw << endl;
            up = y[i];
            dw = div;
            pos = i;
        }
    }

    ///cout << pos << endl;
    ll ans = prod_query(1, 0, n - 1, 0, pos);
    //for (int i = 0; i <= pos; i ++)
      //  ans = (ans * x[i]) % mod;
    ans = (ans * y[pos]) % mod;
    return ans;
}
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];
    }
    build_prod_tree(1, 0, n - 1);
    return action();
}

int updateX(int pos, int val)
{
    x[pos] = val;
    update_prod(1, 0, n - 1, pos);
    return action();
}

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

컴파일 시 표준 에러 (stderr) 메시지

horses.cpp: In function 'll action()':
horses.cpp:61:20: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   61 |     for (int i = n - 2; i >= 0; i --)
      |                  ~~^~~
horses.cpp:64:13: warning: conversion from 'll' {aka 'long long int'} to 'double' may change value [-Wconversion]
   64 |         if (div > 1e9)
      |             ^~~
horses.cpp:79:33: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   79 |     ll ans = prod_query(1, 0, n - 1, 0, pos);
      |                               ~~^~~
horses.cpp:79:41: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   79 |     ll ans = prod_query(1, 0, n - 1, 0, pos);
      |                                         ^~~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:93:29: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   93 |     build_prod_tree(1, 0, n - 1);
      |                           ~~^~~
horses.cpp:94:18: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   94 |     return action();
      |            ~~~~~~^~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:100:25: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  100 |     update_prod(1, 0, n - 1, pos);
      |                       ~~^~~
horses.cpp:101:18: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  101 |     return action();
      |            ~~~~~~^~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:107:18: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
  107 |     return action();
      |            ~~~~~~^~

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