Submission #999648

#	Time	Username	Problem	Language	Result	Execution time	Memory
999648		Alfraganus	Horses (IOI15_horses)	C++17	54 / 100	1569 ms	33964 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;
	}

	void change(int pos, int val, int x, int lx, int rx){
		if(lx + 1 == rx){
			pr[x] = val;
			return;
		}
		int mid = (lx + rx) >> 1;
		if(pos < mid)
			change(pos, val, (x << 1) + 1, lx, mid);
		else
			change(pos, val, (x << 1) + 2, mid, rx);
		pr[x] = (pr[(x << 1) + 1] * pr[(x << 1) + 2]) % mod;
	}

	void change(int pos, int val){
		change(pos, val, 0, 0, size);
	}

	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){
		return get(l, r, 0, 0, size);
	}
};

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;
	s.change(pos, val);
	int n = (int)x.size();
	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 updateY(int pos, int val) {
	y[pos] = val;
	int n = (int)x.size();
	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;
}

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 'void SegTree::change(int, int, int, int, int)':
horses.cpp:32:36: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   32 |  void change(int pos, int val, int x, int lx, int rx){
      |                                ~~~~^
horses.cpp:6:19: note: shadowed declaration is here
    6 | vector<long long> x, y;
      |                   ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:73:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   73 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:73:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   73 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:74:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   74 |    return ans;
      |           ^~~
horses.cpp:82:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   82 |  return ans;
      |         ^~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:91:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   91 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:91:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
   91 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:92:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
   92 |    return ans;
      |           ^~~
horses.cpp:100:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  100 |  return ans;
      |         ^~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:108:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  108 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:108:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  108 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:109:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  109 |    return ans;
      |           ^~~
horses.cpp:117:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  117 |  return ans;
      |         ^~~

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