Submission #1007957

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007957		GrindMachine	Flight to the Ford (BOI22_communication)	C++17	15 / 100	34 ms	2924 KiB

communication

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

/*

read some solutions a long time ago, remember some key ideas from there

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "communication.h"
//
// --- Sample implementation for the task communication ---
//
// To compile this program with the sample grader, place:
//     communication.h communication_sample.cpp sample_grader.cpp
// in a single folder, then open the terminal in this directory (right-click onto an empty spot in the directory,
// left click on "Open in terminal") and enter e.g.:
//     g++ -std=c++17 communication_sample.cpp sample_grader.cpp
// in this folder. This will create a file a.out in the current directory which you can execute from the terminal
// as ./a.out
// See task statement or sample_grader.cpp for the input specification
//

void encode(int n, int k) {
    vector<int> a = {0,6,9,15};
    amax(n,4);
    int x = a[k-1];

    rep(bit,4){
        int b = 0;
        if(x&(1<<bit)) b = 1;
        send(b);
    }
}

std::pair<int, int> decode(int n) {
    vector<int> a = {0,6,9,15};
    vector<vector<int>> possible(4);

    rep(i,4){
        int x = a[i];
        rep(mask,1<<4){
            int pb = -1;
            bool ok = true;

            rep(bit,4){
                int b = 0;
                if(mask&(1<<bit)) b = 1;
                if(b == 1 and pb == 1){
                    ok = false;
                }
                pb = b;
            }

            if(ok){
                possible[i].pb(x^mask);
            }
        }
    }

    int x = 0;
    rep(bit,4){
        x = (x<<1)|receive();
    }

    vector<int> res;
    rep(i,n){
        if(count(all(possible[i]),x)){
            res.pb(i+1);
        }
    }

    assert(!res.empty());
    while(sz(res) < 2){
        res.pb(res[0]);
    }

    return {res[0],res[1]};

    // receive();
    // receive();
    // receive();
}

• Subtask 1: 15 / 15
• Subtask 2: 0 / 85