Submission #58494

#	Time	Username	Problem	Language	Result	Execution time	Memory
58494		E869120	Horses (IOI15_horses)	C++14	100 / 100	920 ms	104352 KiB

horses

#include "horses.h"
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

class RangeMax {
public:
	vector<int>dat; int size_ = 0;
	void init(int sz) {
		size_ = 1;
		while (size_ <= sz) size_ *= 2;
		dat.resize(size_ * 2, 0);
	}
	void update(int p, int x) {
		p += size_; dat[p] = x; p >>= 1;
		while (p >= 1) { dat[p] = max(dat[p * 2], dat[p * 2 + 1]); p >>= 1; }
	}
	int getmax_(int l, int r, int a, int b, int u) {
		if (b <= l || r <= a) return -1;
		if (l <= a && b <= r) return dat[u];
		return max(getmax_(l, r, a, (a + b) >> 1, u * 2), getmax_(l, r, (a + b) >> 1, b, u * 2 + 1));
	}
	int getmax(int l, int r) {
		return getmax_(l, r, 0, size_, 1);
	}
};

int bit[524299];
void add(int pos, int x) {
	pos++;
	while (pos < 524299) { bit[pos] += x; pos += (pos&-pos); }
}
int sum(int pos) {
	int s = 0; pos++;
	while (pos >= 1) { s += bit[pos]; pos -= (pos&-pos); }
	return s;
}

long long N, X[500009], Y[500009], Allval = 0, mod = 1000000007;
RangeMax Q;

long long modpow(long long a, long long b, long long m) {
	long long p = 1, q = a;
	for (int i = 0; i < 31; i++) {
		if ((b&(1LL << i)) != 0) { p *= q; p %= m; }
		q *= q; q %= m;
	}
	return p;
}

long long Div(long long a, long long b, long long m) {
	return (1LL * a*modpow(b, m - 2, m)) % m;
}

int solve() {
	pair<int, int>maxid = make_pair(0, 1);

	long long P = 1, cx = N - 1;
	while (true) {
		// 二分探索 Phase
		long long M = 0, I = sum(cx), J = 0;
		for (int i = 18; i >= 0; i--) {
			if (bit[M + (1 << i)] + J < I) { M += (1 << i); J += bit[M]; }
		}

		// 結果を求める Phase
		long long YY = Q.getmax(M, cx + 1);
		if (maxid.first * P < maxid.second * YY) maxid = make_pair(YY, P);
		P *= X[M]; cx = M - 1;
		if (P > (1LL << 30) || cx < 0) break;
	}

	long long J = Div(Allval, maxid.second, mod);
	J *= maxid.first; J %= mod;
	return J;
}

int init(int NN, int XX[], int YY[]) {
	N = NN; Allval = 1; Q.init(N + 2);
	for (int i = 0; i < N; i++) { X[i] = XX[i]; Allval *= X[i]; Allval %= mod; if (X[i] >= 2) add(i, 1); }
	for (int i = 0; i < N; i++) { Y[i] = YY[i]; Q.update(i, Y[i]); }
	return solve();
}

int updateX(int pos, int val) {	
	Allval = Div(Allval, X[pos], mod); if (X[pos] >= 2) add(pos, -1);
	X[pos] = val;
	Allval *= X[pos]; Allval %= mod; if (X[pos] >= 2) add(pos, 1);
	return solve();
}

int updateY(int pos, int val) {
	Y[pos] = val; Q.update(pos, Y[pos]);
	return solve();
}

Compilation message (stderr)

horses.cpp: In function 'int solve()':
horses.cpp:62:30: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
   long long M = 0, I = sum(cx), J = 0;
                              ^
horses.cpp:68:36: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
   long long YY = Q.getmax(M, cx + 1);
                                    ^
horses.cpp:68:33: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
   long long YY = Q.getmax(M, cx + 1);
                              ~~~^~~
horses.cpp:76:9: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return J;
         ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:80:31: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  N = NN; Allval = 1; Q.init(N + 2);
                             ~~^~~
horses.cpp:82:61: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  for (int i = 0; i < N; i++) { Y[i] = YY[i]; Q.update(i, Y[i]); }
                                                          ~~~^
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:94:35: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  Y[pos] = val; Q.update(pos, Y[pos]);
                              ~~~~~^

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