Submission #999651

#	Time	Username	Problem	Language	Result	Execution time	Memory
999651		Alfraganus	Horses (IOI15_horses)	C++17	0 / 100	152 ms	52816 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, mx;

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

	void build(int ind, int lx, int rx){
		if(lx + 1 == rx){
			if(lx < x.size())
				pr[ind] = x[lx], mx[ind] = y[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;
		mx[ind] = max(mx[(ind << 1) + 1], mx[(ind << 1) + 2]);
	}

	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);
	}

	void set(int pos, int val, int x, int lx, int rx){
		if(lx + 1 == rx){
			mx[x] = val;
			return;
		}
		int mid = (lx + rx) >> 1;
		set(pos, val, (x << 1) + 1, lx, mid);
		set(pos, val, (x << 1) + 1, mid, rx);
		mx[x] = max(mx[(x << 1) + 1], mx[(x << 1) + 2]);
	}

	void set(int pos, int val){
		set(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);
	}

	int res(int l, int r, int x, int lx, int rx){
		if(l <= lx and rx <= r)
			return mx[x];
		if(r <= lx or rx <= l)
			return 0;
		int mid = (lx + rx) >> 1;
		return max(res(l, r, (x << 1) + 1, lx, mid), res(l, r, (x << 1) + 2, mid, rx));
	}

	int res(int l, int r){
		return res(l, r, 0, 0, size);
	}
};

SegTree s;
set<int> st;

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];
	st.insert(-1);
	for(int i = 0; i < n; i ++)
		if(x[i] != 1)
			st.insert(i);
	s.init();
	long long y1 = s.res((*--st.end()) + 1, n), p = 1, ans = (s.res((*--st.end()) + 1, n) * s.get(0, *--st.end() + 1)) % mod;
	auto cur = --st.end(), prev = cur;
	while(1){
		if(prev == st.begin())
			return ans;
		prev --;
		p = p * x[*cur];
		if(p > 1e9 or y1 * p > 1e9)
			return ans;
		if(s.res(*prev + 1, *cur + 1) > y1 * p){
			y1 = s.res(*prev + 1, *cur + 1);
			p = 1;
			ans = (y1 * s.get(0, *prev + 1)) % mod;
		}
		cur --;
	}
	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:23:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |    if(lx < x.size())
      |       ~~~^~~~~~~~~~
horses.cpp: In member function 'void SegTree::change(int, int, int, int, int)':
horses.cpp:34:36: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   34 |  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 member function 'void SegTree::set(int, int, int, int, int)':
horses.cpp:51:33: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   51 |  void set(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 member function 'int SegTree::res(int, int, int, int, int)':
horses.cpp:79:28: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   79 |  int res(int l, int r, int x, int lx, int rx){
      |                        ~~~~^
horses.cpp:6:19: note: shadowed declaration is here
    6 | vector<long long> x, y;
      |                   ^
horses.cpp:81:15: warning: conversion from '__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type' {aka 'long long int'} to 'int' may change value [-Wconversion]
   81 |    return mx[x];
      |               ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:110:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  110 |    return ans;
      |           ^~~
horses.cpp:113:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  113 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:113:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  113 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:114:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  114 |    return ans;
      |           ^~~
horses.cpp:122:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  122 |  return ans;
      |         ^~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:131:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  131 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:131:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  131 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:132:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  132 |    return ans;
      |           ^~~
horses.cpp:140:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  140 |  return ans;
      |         ^~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:148:6: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  148 |   if(p > 1e9 or y1 * p > 1e9)
      |      ^
horses.cpp:148:20: warning: conversion from 'long long int' to 'double' may change value [-Wconversion]
  148 |   if(p > 1e9 or y1 * p > 1e9)
      |                 ~~~^~~
horses.cpp:149:11: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  149 |    return ans;
      |           ^~~
horses.cpp:157:9: warning: conversion from 'long long int' to 'int' may change value [-Wconversion]
  157 |  return ans;
      |         ^~~

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