Submission #40279

#	Time	Username	Problem	Language	Result	Execution time	Memory
40279		szawinis	Horses (IOI15_horses)	C++14	17 / 100	127 ms	58296 KiB

horses

#include "horses.h"
#include <algorithm>
#include <cmath>
using namespace std;
using ll = long long;
const int N = 1 << 19;
const ll MOD = 1e9 + 7;

ll modPow(ll b, ll e) {
  if (!e)
    return 1;
  if (e == 1)
    return b;
  return modPow(b * b % MOD, e >> 1) * modPow(b, e & 1) % MOD;
}

struct node {
  double comp;
  ll val;
  bool lazy_needed;
  void merge(node rhs) {
    lazy_needed = true;
    comp += rhs.comp;
    val = 1ll * val * rhs.val % MOD;
  }
  bool operator>(const node &rhs) const {
    if (comp > rhs.comp)
      return true;
    if (comp == rhs.comp && val > rhs.val)
      return true;
    return false;
  }
} t[2 * N], lz[2 * N];

void build(int i, int l, int r) {
  if (l == r)
    return;
  int mid = l + r >> 1;
  build(i << 1, l, mid);
  build(i << 1 | 1, mid + 1, r);
  if (t[i << 1] > t[i << 1 | 1])
    t[i] = t[i << 1];
  else
    t[i] = t[i << 1 | 1];
}

void apply(int i) {
  t[i].merge(lz[i]);
  if (i < N) {
    lz[i << 1].merge(lz[i]);
    lz[i << 1 | 1].merge(lz[i]);
  }
  lz[i].lazy_needed = false;
  lz[i].comp = 0, lz[i].val = 1;
}

void update(int i, int l, int r, int tl, int tr, node v) {
  if (lz[i].lazy_needed)
    apply(i);
  if (l > tr || r < tl)
    return;
  if (l >= tl && r <= tr) {
    lz[i].merge(v);
    apply(i);
    return;
  }
  int mid = l + r >> 1;
  update(i << 1, l, mid, tl, tr, v);
  update(i << 1 | 1, mid + 1, r, tl, tr, v);
  if (t[i << 1] > t[i << 1 | 1])
    t[i] = t[i << 1];
  else
    t[i] = t[i << 1 | 1];
}

int n, x[N], y[N];
int init(int _n, int _x[], int _y[]) {
  n = _n;
  copy(_x, _x + n, x);
  copy(_y, _y + n, y);
  node curr = {0, 1, 0};
  for (int i = 0; i < n; i++) {
    curr.merge((node){(double)log2(x[i]), x[i]});
    t[N + i] = curr;
    t[N + i].merge((node){(double)log2(y[i]), y[i]});
  }
  build(1, 0, N - 1);
  return t[1].val;
}

int updateX(int pos, int val) {
  double ncomp = (double)log2(val) - (double)log2(x[pos]);
  ll nval = 1ll * val * modPow(x[pos], MOD - 2) % MOD;
	x[pos] = val;
  update(1, 0, N - 1, pos, N - 1, (node){ncomp, nval});
  return t[1].val;
}

int updateY(int pos, int val) {
  double ncomp = (double)log2(val) - (double)log2(y[pos]);
  ll nval = 1ll * val * modPow(y[pos], MOD - 2) % MOD;
	y[pos] = val;
  update(1, 0, N - 1, pos, pos, (node){ncomp, nval});
  return t[1].val;
}

Compilation message (stderr)

horses.cpp: In function 'void build(int, int, int)':
horses.cpp:38:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   int mid = l + r >> 1;
               ^
horses.cpp: In function 'void update(int, int, int, int, int, node)':
horses.cpp:67:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   int mid = l + r >> 1;
               ^
horses.cpp: In function 'int init(int, int*, int*)':
horses.cpp:83:47: warning: missing initializer for member 'node::lazy_needed' [-Wmissing-field-initializers]
     curr.merge((node){(double)log2(x[i]), x[i]});
                                               ^
horses.cpp:85:51: warning: missing initializer for member 'node::lazy_needed' [-Wmissing-field-initializers]
     t[N + i].merge((node){(double)log2(y[i]), y[i]});
                                                   ^
horses.cpp:88:15: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
   return t[1].val;
               ^
horses.cpp: In function 'int updateX(int, int)':
horses.cpp:95:53: warning: missing initializer for member 'node::lazy_needed' [-Wmissing-field-initializers]
   update(1, 0, N - 1, pos, N - 1, (node){ncomp, nval});
                                                     ^
horses.cpp:96:15: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
   return t[1].val;
               ^
horses.cpp: In function 'int updateY(int, int)':
horses.cpp:103:51: warning: missing initializer for member 'node::lazy_needed' [-Wmissing-field-initializers]
   update(1, 0, N - 1, pos, pos, (node){ncomp, nval});
                                                   ^
horses.cpp:104:15: warning: conversion to 'int' from 'll {aka long long int}' may alter its value [-Wconversion]
   return t[1].val;
               ^

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