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Submission #601732

# Submission time Handle Problem Language Result Execution time Memory
601732 2022-07-22T09:28:07 Z 박상훈(#8471) Flight to the Ford (BOI22_communication) C++17
78 / 100
 4698 ms 2224 KB 
#include "communication.h"
#include <bits/stdc++.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
//

using namespace std;
typedef long long ll;
int valid[128];

int _find(const vector<pair<int, int>> &V, int S, int k, int X){
    int cur = V[0].first;
    int pt = 0;
    int ret = 0;

    int rem = S / k;
    if (S%k) rem++;

    while(true){
        int r = min(cur+rem-1, V[pt].second);
        if (X>=cur && X<=r) return ret;

        S -= r-cur+1;
        rem -= r-cur+1;
        if (rem==0){
            --k;
            assert(k);

            rem = S/k;
            if (S%k) rem++;
            ret++;
        }

        cur = r+1;
        if (cur>V[pt].second){
            ++pt;
            cur = V[pt].first;
        }
    }
    assert(0);
}

void _modify(vector<pair<int, int>> &V, int &S, int k, int val){
    vector<pair<int, int>> ret;
    int retS = 0;

    int cur = V[0].first;
    int pt = 0, idx = 0;

    int rem = S / k;
    if (S%k) rem++;

    while(true){
        int r = min(cur+rem-1, V[pt].second);
        if (valid[idx^val]){
            //printf(" %d %d\n", idx, val);
            ret.emplace_back(cur, r);
            retS += r-cur+1;
        }

        S -= r-cur+1;
        rem -= r-cur+1;
        if (rem==0){
            --k;
            if (!k) break;

            rem = S/k;
            if (S%k) rem++;
            idx++;
        }

        cur = r+1;
        if (cur>V[pt].second){
            ++pt;
            cur = V[pt].first;
        }
    }

    swap(V, ret);
    swap(S, retS);
}

vector<int> get_last(const vector<pair<int, int>> &V){
    vector<int> ret;
    for (auto &[l, r]:V){
        for (int i=l;i<=r;i++) ret.push_back(i);
    }
    assert(ret.size()==3);
    return ret;
}

void process(vector<pair<int, int>> &V, int &S, int k, int encode, int t){
    while(S>=k){
        int val = 0;
        if (encode) val = _find(V, S, k, encode);
        int rval = 0;

        if (encode){
            for (int i=0;i<t;i++){
                if (val&(1<<i)) rval |= (send(1)<<i);
                else rval |= (send(0)<<i);
            }
        }

        else{
            for (int i=0;i<t;i++){
                rval |= (receive()<<i);
            }
        }


        _modify(V, S, k, rval);

        //for (auto &[l, r]:V) printf("[%d, %d] ", l, r);
        //printf("-> %d\n", S);
    }
}

void encode(int N, int X) {

    for (int i=0;i<1024;i++){
        valid[i] = 1;
        for (int j=0;j<9;j++) if ((i&(1<<j)) && (i&(1<<(j+1)))) valid[i] = 0;
    }

    vector<pair<int, int>> V = {{1, N}};
    int S = N;

    //process(V, S, 1024, X, 10);
    process(V, S, 512, X, 9);
    process(V, S, 256, X, 8);
    process(V, S, 128, X, 7);
    process(V, S, 64, X, 6);
    process(V, S, 32, X, 5);
    process(V, S, 16, X, 4);
    process(V, S, 8, X, 3);
    process(V, S, 4, X, 2);




    vector<int> last = get_last(V);
    X = find(last.begin(), last.end(), X) - last.begin() + 1;
    assert(X<=3);
    string s[4] = {"", "10", "11", "01"};

    bool flag = 0;
    for (int i=0;i<3;i++){
        if (!flag) flag = (((s[X][0]-'0')^1) != send((s[X][0]-'0') ^ 1));
        else{
            send(s[X][1]-'0');
            flag = 0;
        }
    }
}

std::pair<int, int> decode(int N) {
    for (int i=0;i<1024;i++){
        valid[i] = 1;
        for (int j=0;j<9;j++) if ((i&(1<<j)) && (i&(1<<(j+1)))) valid[i] = 0;
    }

    vector<pair<int, int>> V = {{1, N}};
    int S = N;

    //process(V, S, 1024, 0, 10);
    process(V, S, 512, 0, 9);
    process(V, S, 256, 0, 8);
    process(V, S, 128, 0, 7);
    process(V, S, 64, 0, 6);
    process(V, S, 32, 0, 5);
    process(V, S, 16, 0, 4);
    process(V, S, 8, 0, 3);
    process(V, S, 4, 0, 2);

    vector<int> last = get_last(V);
    vector<int> v;
    for (int i=0;i<3;i++){
        int x = receive();
        v.push_back(x);
        if (i && v[i-1]==v[i]){
            if (v[i]==1) return {last[1], last[2]};
            else return {last[0], last[1]};
        }
    }
    return {last[0], last[2]};
}

Compilation message

communication.cpp: In function 'void encode(int, int)':
communication.cpp:131:18: warning: iteration 128 invokes undefined behavior [-Waggressive-loop-optimizations]
  131 |         valid[i] = 1;
      |         ~~~~~~~~~^~~
communication.cpp:130:19: note: within this loop
  130 |     for (int i=0;i<1024;i++){
      |                  ~^~~~~
communication.cpp: In function 'std::pair<int, int> decode(int)':
communication.cpp:168:18: warning: iteration 128 invokes undefined behavior [-Waggressive-loop-optimizations]
  168 |         valid[i] = 1;
      |         ~~~~~~~~~^~~
communication.cpp:167:19: note: within this loop
  167 |     for (int i=0;i<1024;i++){
      |                  ~^~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 1728 KB Output is correct
2 Correct 18 ms 1924 KB Output is correct
3 Correct 20 ms 1664 KB Output is correct
4 Correct 14 ms 1784 KB Output is correct
5 Correct 21 ms 1812 KB Output is correct
6 Correct 43 ms 2124 KB Output is correct
7 Correct 58 ms 1800 KB Output is correct

Subtask #2
62.99996 / 85.0

# Verdict Execution time Memory Grader output
1 Partially correct 794 ms 1668 KB Output is partially correct
2 Partially correct 461 ms 1764 KB Output is partially correct
3 Partially correct 675 ms 1664 KB Output is partially correct
4 Partially correct 1052 ms 1668 KB Output is partially correct
5 Partially correct 813 ms 1784 KB Output is partially correct
6 Partially correct 678 ms 1808 KB Output is partially correct
7 Partially correct 2987 ms 1984 KB Output is partially correct
8 Partially correct 4646 ms 2084 KB Output is partially correct
9 Partially correct 4171 ms 2144 KB Output is partially correct
10 Partially correct 3798 ms 2092 KB Output is partially correct
11 Partially correct 3996 ms 2144 KB Output is partially correct
12 Partially correct 4155 ms 2224 KB Output is partially correct
13 Partially correct 4052 ms 2092 KB Output is partially correct
14 Partially correct 4007 ms 2080 KB Output is partially correct
15 Partially correct 2146 ms 1760 KB Output is partially correct
16 Partially correct 4698 ms 1996 KB Output is partially correct
17 Partially correct 1190 ms 1924 KB Output is partially correct
18 Partially correct 1112 ms 1976 KB Output is partially correct
19 Partially correct 1084 ms 1908 KB Output is partially correct
20 Partially correct 1101 ms 2064 KB Output is partially correct
21 Partially correct 992 ms 1824 KB Output is partially correct
22 Partially correct 1136 ms 2008 KB Output is partially correct
23 Partially correct 1791 ms 1848 KB Output is partially correct
24 Correct 15 ms 1856 KB Output is correct
25 Correct 18 ms 1796 KB Output is correct
26 Correct 15 ms 1820 KB Output is correct
27 Correct 13 ms 1872 KB Output is correct
28 Correct 16 ms 1840 KB Output is correct
29 Correct 30 ms 1732 KB Output is correct
30 Correct 59 ms 1752 KB Output is correct