Submission #160265

#	Time	Username	Problem	Language	Result	Execution time	Memory
160265		bortoz	Horses (IOI15_horses)	C++17	100 / 100	383 ms	31864 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second

constexpr int MAXN = 1 << 19;
constexpr int MOD = 1e9 + 7;

pair<int, bool> segX[2 * MAXN];
int segM[2 * MAXN];
int Y[MAXN];

pair<int, bool> joinX(pair<int, bool>& a, pair<int, bool>& b) {
	ll r = 1ll * a.fi * b.fi;
	bool o = (r >= MOD) || a.se || b.se;
	return make_pair(r % MOD, o);
}

pair<int, bool> queryX(int l, int r) {
	pair<int, bool> ans{1, false};
	for (l += MAXN, r += MAXN; l < r; l /= 2, r /= 2) {
		if (l & 1) ans = joinX(ans, segX[l++]);
		if (r & 1) ans = joinX(ans, segX[--r]);
	}
	return ans;
}

int joinM(int a, int b) {
	pair<int, bool> mulX = queryX(a + 1, b + 1);
	if (mulX.se) return b;
	return Y[a] > 1ll * mulX.fi * Y[b] ? a : b;
}

int init(int N, int* X, int*_Y) {
	copy(_Y, _Y + N, Y);
	for (int i = 0; i < N; i++) {
		segX[i + MAXN] = make_pair(X[i], false);
	}
	iota(segM + MAXN, segM + 2 * MAXN, 0);
	for (int i = MAXN - 1; i > 0; i--) {
		segX[i] = joinX(segX[2 * i], segX[2 * i + 1]);
		segM[i] = joinM(segM[2 * i], segM[2 * i + 1]);
	}
	return 1ll * queryX(0, segM[1] + 1).fi * Y[segM[1]] % MOD;
}

int updateX(int pos, int val) {
	for (segX[pos += MAXN] = make_pair(val, false); pos > 1; pos /= 2) {
		segX[pos / 2] = joinX(segX[pos & -2], segX[pos | 1]);
		segM[pos / 2] = joinM(segM[pos & -2], segM[pos | 1]);
	}
	return 1ll * queryX(0, segM[1] + 1).fi * Y[segM[1]] % MOD;
}

int updateY(int pos, int val) {
	for (Y[pos] = val, pos += MAXN; pos > 1; pos /= 2) {
		segX[pos / 2] = joinX(segX[pos & -2], segX[pos | 1]);
		segM[pos / 2] = joinM(segM[pos & -2], segM[pos | 1]);
	}
	return 1ll * queryX(0, segM[1] + 1).fi * Y[segM[1]] % MOD;
}

Compilation message (stderr)

horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:46:54: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return 1ll * queryX(0, segM[1] + 1).fi * Y[segM[1]] % MOD;
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:54:54: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return 1ll * queryX(0, segM[1] + 1).fi * Y[segM[1]] % MOD;
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:62:54: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return 1ll * queryX(0, segM[1] + 1).fi * Y[segM[1]] % MOD;
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~

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