Submission #285079

#	Time	Username	Problem	Language	Result	Execution time	Memory
285079		Shafin666	Horses (IOI15_horses)	C++14	100 / 100	238 ms	58488 KiB

horses

#include "horses.h"
#include <bits/stdc++.h>
#define pb push_back
#define pii pair<ll, ll>
#define nyan "(=^･ω･^=)"
#define read_input         freopen("in.txt","r", stdin)
#define print_output       freopen("out.txt","w", stdout)
typedef long long ll;
typedef long double ld;
using namespace std;

const int maxn = 5e5+10, mod = 1e9+7;
ll x[maxn], y[maxn], n;

struct node {
	double lg; // log x0 + log x1 + ...
	double mxlg; // max log (x0 x1 x2 .... xi * yi)
	ll mul; // x0 x1 x2 ... % mod
	ll mxmul; // max x0 x1 ... xi * yi
} tree[4 * maxn];

node merge(node a, node b) {
	node ret;
	ret.lg = a.lg + b.lg;
	ret.mul = (a.mul * b.mul) % mod;

	if(a.mxlg <= a.lg + b.mxlg) {
		ret.mxlg = a.lg + b.mxlg;
		ret.mxmul = (a.mul * b.mxmul) % mod;
	} else {
		ret.mxlg = a.mxlg;
		ret.mxmul = a.mxmul;
	}
	return ret;
}

void build(int at, int L, int R) {
	if(L == R) {
		node now;
		now.lg = log(x[L]);
		now.mxlg = log(x[L] * y[L]);
		now.mul = x[L];
		now.mxmul = (x[L] * y[L]) % mod;
		tree[at] = now;
		return;
	}
	int mid = L + R >> 1;
	build(at<<1, L, mid); build(at<<1|1, mid+1, R);
	tree[at] = merge(tree[at<<1], tree[at<<1|1]);
}

void update(int at, int L, int R, int idx) {
	if(L == R) {
		node now;
		now.lg = log(x[L]);
		now.mxlg = log(x[L] * y[L]);
		now.mul = x[L];
		now.mxmul = (x[L] * y[L]) % mod;
		tree[at] = now;
		return;
	}
	int mid = L + R >> 1;
	if(idx <= mid) update(at<<1, L, mid, idx);
	else update(at<<1|1, mid+1, R, idx);

	tree[at] = merge(tree[at<<1], tree[at<<1|1]);
}

int init(int N, int X[], int Y[]) {
	n = N;
	for(int i = 0; i < N; i++) x[i] = X[i], y[i] = Y[i];

	build(1, 0, n-1);
	return tree[1].mxmul;
}

int updateX(int pos, int val) {	
	x[pos] = val;

	update(1, 0, n-1, pos);
	return tree[1].mxmul;
}

int updateY(int pos, int val) {
	y[pos] = val;

	update(1, 0, n-1, pos);
	return tree[1].mxmul;
}

Compilation message (stderr)

horses.cpp: In function 'void build(int, int, int)':
horses.cpp:47:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   47 |  int mid = L + R >> 1;
      |            ~~^~~
horses.cpp: In function 'void update(int, int, int, int)':
horses.cpp:62:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   62 |  int mid = L + R >> 1;
      |            ~~^~~
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:73:15: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   73 |  build(1, 0, n-1);
      |              ~^~
horses.cpp:74:17: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   74 |  return tree[1].mxmul;
      |         ~~~~~~~~^~~~~
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:80:16: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   80 |  update(1, 0, n-1, pos);
      |               ~^~
horses.cpp:81:17: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   81 |  return tree[1].mxmul;
      |         ~~~~~~~~^~~~~
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:87:16: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   87 |  update(1, 0, n-1, pos);
      |               ~^~
horses.cpp:88:17: warning: conversion from 'll' {aka 'long long int'} to 'int' may change value [-Wconversion]
   88 |  return tree[1].mxmul;
      |         ~~~~~~~~^~~~~

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