Submission #225727

#	Time	Username	Problem	Language	Result	Execution time	Memory
225727		staniewzki	Horses (IOI15_horses)	C++17	17 / 100	138 ms	17272 KiB

horses

#include<bits/stdc++.h>
using namespace std;
 
#define REP(i, n) for(int i = 0; i < n; i++)
#define ST first
#define ND second
 
using PII = pair<int, int>;

#include "horses.h"

const int mod = int(1e9 + 7);

int mul(int a, int b) {
	return (long long) a * b % mod;
}

PII operator+(PII a, PII b) {
	return {
		max(a.ST, mul(a.ND, b.ST)),
		mul(a.ND, b.ND)
	};
}

struct Tree {
	vector<PII> tree;
	int sz = 1;

	Tree(int n = 0) {
		while(sz < n) sz *= 2;
		tree.resize(sz * 2);
	}

	void update(int pos) {
		pos += sz;
		while(pos /= 2)
			tree[pos] = tree[pos * 2] + tree[pos * 2 + 1];
	}

	PII& operator[](int pos) { return tree[pos + sz]; }
	int query() { return tree[1].ST; }
} tree;

int init(int N, int X[], int Y[]) {
	tree = Tree(N + 1);
	REP(i, N) tree[i + 1].ST = Y[i];
	REP(i, N) tree[i].ND = X[i];
	REP(i, N + 1) tree.update(i);
	return tree.query();
}

int updateX(int pos, int val) {	
	tree[pos].ND = val;
	tree.update(pos);
	return tree.query();
}

int updateY(int pos, int val) {
	tree[++pos].ST = val;
	tree.update(pos);
	return tree.query();
}

Compilation message (stderr)

horses.cpp: In function 'int mul(int, int)':
horses.cpp:15:27: warning: conversion to 'int' from 'long long int' may alter its value [-Wconversion]
  return (long long) a * b % mod;
         ~~~~~~~~~~~~~~~~~~^~~~~

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