Submission #999647

#	Time	Username	Problem	Language	Result	Execution time	Memory
999647		Alfraganus	Horses (IOI15_horses)	C++17	17 / 100	1506 ms	20384 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;

const long long mod = 1e9 + 7;
vector<long long> x, y;

struct SegTree {

	int size = 1;
	vector<long long> pr;

	void init(){
		while(size < (int)x.size())
			size <<= 1;
		pr.resize(size << 1, 1);
		build(0, 0, size);
	}

	void build(int ind, int lx, int rx){
		if(lx + 1 == rx){
			if(lx < x.size())
				pr[ind] = x[lx];
			return;
		}
		int mid = (lx + rx) >> 1;
		build((ind << 1) + 1, lx, mid);
		build((ind << 1) + 2, mid, rx);
		pr[ind] = (pr[(ind << 1) + 1] * pr[(ind << 1) + 2]) % mod;
	}

	long long get(int l, int r, int ind, int lx, int rx){
		if(l <= lx and rx <= r)
			return pr[ind];
		if(r <= lx or rx <= l)
			return 1ll;
		int mid = (lx + rx) >> 1;
		return (get(l, r, (ind << 1) + 1, lx, mid) * get(l, r, (ind << 1) + 2, mid, rx)) % mod;
	}

	long long get(int l, int r){
		long long ans = 1;
		for(int i = l; i < r; i ++)
			ans = (ans * x[i]) % mod;
		long long y = get(l, r, 0, 0, size);
		if(ans != y){
			while(1){

			}
		}
		return y;
	}
};

SegTree s;

int init(int n, int X[], int Y[]) {
	x.resize(n);
	y.resize(n);
	for(int i = 0; i < n; i ++)
		x[i] = X[i], y[i] = Y[i];
	s.init();
	long long y1 = 0, p = 1, ans = 1;
	for(int i = n - 1; i >= 0; i --){
		if(p > 1e9 or y1 * p > 1e9)
			return ans;
		if(y[i] > y1 * p){
			y1 = y[i];
			p = 1;
			ans = (y1 * s.get(0, i + 1)) % mod;
		}
		p = p * x[i];
	}
	return ans;
}

int updateX(int pos, int val) {
	x[pos] = val;
	long long ans = 1, p = 1;
	for(int i = 0; i < (int)x.size(); i ++)
		p = (p * x[i]) % mod, ans = (max(ans, p * y[i])) % mod;
	int res = ans;
	return res;
}

int updateY(int pos, int val) {
	y[pos] = val;
	long long ans = 1, p = 1;
	for(int i = 0; i < (int)y.size(); i ++)
		p = (p * x[i]) % mod, ans = (max(ans, p * y[i])) % mod;
	int res = ans;
	return res;
}

Compilation message (stderr)

horses.cpp: In member function 'void SegTree::build(int, int, int)':
horses.cpp:22:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |    if(lx < x.size())
      |       ~~~^~~~~~~~~~
horses.cpp: In member function 'long long int SegTree::get(int, int)':
horses.cpp:45:13: warning: declaration of 'y' shadows a global declaration [-Wshadow]
   45 |   long long y = get(l, r, 0, 0, size);
      |             ^
horses.cpp:6:22: note: shadowed declaration is here
    6 | vector<long long> x, y;
      |                      ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:65:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   65 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:65:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   65 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:66:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   66 |    return ans;
      |           ^~~
horses.cpp:74:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   74 |  return ans;
      |         ^~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:82:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   82 |  int res = ans;
      |            ^~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:91:12: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   91 |  int res = ans;
      |            ^~~

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