Submission #599781

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
599781	2022-07-19T21:45:41 Z	Mounir	Flight to the Ford (BOI22_communication)	C++17	15 / 100	51 ms	1796 KB

communication

#include "communication.h"
#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define chmax(x, v) x = max(x, v)
#define chmin(x, v) x = min(x, v)
#define pb push_back
#define pii pair<int, int>
#define sz(x) (int)x.size()
#define x first
#define y second
using namespace std;
 /*
vector<int> bits;
bool modif = false;
int send(int bit){
      bool tom = rand()%2;
      if (modif) tom = false;
      modif = tom;
      bits.pb(bit^tom);
      return bit^tom;
}

int receive(){
      int to = bits.back();
      bits.pop_back();
      return to;
}
*/
void encode(int N, int X){
      if (X == 1){
            for (int i = 0; i < 6; ++i)
                  int ans = send(0);
      }
      else if (X == 2){
            for (int i = 0;  i < 6; ++i)
                  int ans = send(1);
      }
      else {
            for (int i = 0; i < 6; ++i)
                  int ans = send(i%3 == 0);
      }
}

pii decode(int N){
      vector<int> vals;
      for (int i = 0; i < 6; ++i)
            vals.pb(receive());
      
      set<int> possibles;
      for (int mask = 0; mask < (1 << 6); ++mask){
            bool valid = true;
            vector<int> inds;
            for (int i = 0; i < 6; ++i){
                  if ((mask&(1 << i)) > 0)      
                        inds.pb(i);
            }
 
            for (int i = 0; i < sz(inds) - 1; ++i)
                  valid &= (inds[i] != inds[i + 1] - 1);
            if (!valid) continue;
         /*   cout << "mask " << endl;
            for (int i : inds)
                  cout << i << " ";
            cout << endl;*/
            vector<int> change = vals;
            for (int ind : inds)    
                  change[ind] ^= 1;
            bool un = true, deux = true, trois = true;
            for (int i = 0; i < 6; ++i){
                  un &= change[i] == 0;
                  deux &= change[i] == 1;
                  trois &= !(change[i]^(i%3 == 0));
            }
/*
            for (int i : change)
                  cout << i;
            cout << endl;
            for (int i = 0; i < 6; ++i)
                  cout << (change[i]^(i%3 == 0));
            cout << endl;
*/
            if (un)
                  possibles.insert(1);
            if (deux)
                  possibles.insert(2);
            if (trois)
                  possibles.insert(3);
      }

     // cout << sz(possibles) << endl;
      
      vector<int> v;
      for (int a : possibles)
            v.pb(a);
      if (sz(v) == 2)
            return {v[0], v[1]};
      else if (sz(v) == 1)
            return {v[0], 1};
      else 
            return {-1, -1};
}

Compilation message

communication.cpp: In function 'void encode(int, int)':
communication.cpp:32:23: warning: unused variable 'ans' [-Wunused-variable]
   32 |                   int ans = send(0);
      |                       ^~~
communication.cpp:36:23: warning: unused variable 'ans' [-Wunused-variable]
   36 |                   int ans = send(1);
      |                       ^~~
communication.cpp:40:23: warning: unused variable 'ans' [-Wunused-variable]
   40 |                   int ans = send(i%3 == 0);
      |                       ^~~

Subtask #1

15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	11 ms	1700 KB	Output is correct
2	Correct	18 ms	1740 KB	Output is correct
3	Correct	17 ms	1736 KB	Output is correct
4	Correct	10 ms	1740 KB	Output is correct
5	Correct	10 ms	1796 KB	Output is correct
6	Correct	33 ms	1760 KB	Output is correct
7	Correct	51 ms	1692 KB	Output is correct

Subtask #2

0.0 / 85.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	31 ms	200 KB	Not correct
2	Halted	0 ms	0 KB	-