Submission #902660

#	Time	Username	Problem	Language	Result	Execution time	Memory
902660		nguyentunglam	Broken Device (JOI17_broken_device)	C++17	83 / 100	39 ms	2804 KiB

Anna

#include "Annalib.h"
#include<bits/stdc++.h>
using namespace std;

namespace {
  mt19937 rng(148171801350179);
}

void Anna( int n, long long x, int k, int p[] ){
  vector<bool> broken(n);
  vector<int> order(n);
  for(int i = 0; i < n; i++) order[i] = i;
  shuffle(order.begin(), order.end(), rng);
  for(int i = 0; i < n; i++) broken[i] = 0;
  for(int i = 0; i < k; i++) broken[p[i]] = 1;

  for(int i = 0, pre = 0, j = 59; i < n; i++) {
    if (broken[order[i]] || j < 0) {
      Set(order[i], 0);
      continue;
    }
    bool a = x >> j & 1;
    bool b = i - pre & 1;
    if (a == b) {
      pre = i;
      j--;
      Set(order[i], 1);
    }
    else Set(order[i], 0);
  }
}

Bruno

#include "Brunolib.h"
#include<bits/stdc++.h>
using namespace std;

namespace {
mt19937 rng(148171801350179);

}

long long Bruno( int n, int a[] ){
  long long x = 0;
  vector<int> order(n);
  for(int i = 0; i < n; i++) order[i] = i;
  shuffle(order.begin(), order.end(), rng);
//  for(int i = 0; i < n; i++) cout << order[i] << " "; cout << endl;
  for(int i = 0, pre = 0, j = 59; i < n && j >= 0; i++) if (a[order[i]]) {
    bool bit = i - pre & 1;
    if (bit) x |= (1LL << j);
    j--;
    pre = i;
  }
//  cout << "answer :" << x << endl;
  return x;
}

Compilation message (stderr)

Anna.cpp: In function 'void Anna(int, long long int, int, int*)':
Anna.cpp:23:16: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   23 |     bool b = i - pre & 1;
      |              ~~^~~~~

Bruno.cpp: In function 'long long int Bruno(int, int*)':
Bruno.cpp:17:18: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   17 |     bool bit = i - pre & 1;
      |                ~~^~~~~

• Subtask 1: 83 / 100