Submission #1188047

#	Time	Username	Problem	Language	Result	Execution time	Memory
1188047		Zbyszek99	Flight to the Ford (BOI22_communication)	C++20	74 / 100	1162 ms	3160 KiB

communication

#include"communication.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

const int BIT = 30;

void encode(int N, int X) 
{
    vector<int> bits;
    rep(i,BIT)
    {
        if(X & (1 << i)) bits.pb(1);
        else bits.pb(0);
    }
    int prev = 0;
    rep2(i,1,BIT-1)
    {
      //  cout << prev << " " << i << " sent\n";
        int v0 = send(bits[prev]);
        int v1 = send(bits[i]);
        int v2 = send(bits[i]);
        int v3 = send(bits[prev]);
        if(v1 == v2)
        {
            continue;
        }
        else
        {
            prev = i;
        }
    }
}

pair<int,pii> prev_bit[BIT];

pii decode(int N) 
{
    int prev = 0;
    prev_bit[0] = {-1,{-1,-1}};
    vi bits(BIT,-1);
    rep2(i,1,BIT-1)
    {
        int v0 = receive();
        int v1 = receive();
        int v2 = receive();
        int v3 = receive();
        if(v1 == v2)
        {
            bits[i] = v1;
            continue;
        }
        else
        {
            if(v0 == v3)
            {
                bits[prev] = v0;
                int cur = prev;
                int cur_s = v0;
                while(prev_bit[cur].ff != -1)
                {
                    if(prev_bit[cur].ss.ff == cur_s)
                    {
                        cur_s = prev_bit[cur].ss.ss ^ 1;
                    }
                    else
                    {
                        cur_s = prev_bit[cur].ss.ss;
                    }
                    bits[prev_bit[cur].ff] = cur_s;
                    cur = prev_bit[cur].ff;
                }
                prev = i;
                prev_bit[i] = {-1,{-1,-1}};
            }
            else
            {
                prev_bit[i] = {prev,{v2,v3}};
                prev = i;
            }
        }
    }
  //  rep(i,BIT)
  //  {
  //      cout << bits[i] << " ";
  //  }
  ///  cout << " bits\n";
    int ans = 0;
    rep(bit,BIT)
    {
        if(bits[bit] != -1) ans += bits[bit] * (1 << bit);
    }
    int rand_cost = 0;
    int total_rand_cost = (1 << prev);
    int cur = prev;
    int cur_s = 0;
    while(prev_bit[cur].ff != -1)
    {
      //  cout << cur << " prev\n";
        if(prev_bit[cur].ss.ff == cur_s)
        {
            cur_s = prev_bit[cur].ss.ss ^ 1;
        }
        else
        {
            cur_s = prev_bit[cur].ss.ss;
        }
        total_rand_cost += (1 << prev_bit[cur].ff);
        rand_cost += (1 << prev_bit[cur].ff) * cur_s;
       // cout << prev_bit[cur].ff << " new_prev\n";
        bits[prev_bit[cur].ff] = cur_s;
        cur = prev_bit[cur].ff;
    }
   // cout << ans + rand_cost << " " << ans + (rand_cost ^ total_rand_cost) << " " << ans << " " << rand_cost << " " << total_rand_cost << " com\n";
    return {min(max(1,ans + rand_cost),N), min(N,max(1,ans + (rand_cost ^ total_rand_cost)))};
}

• Subtask 1: 15 / 15
• Subtask 2: 59 / 85