Submission #1291791

#	Time	Username	Problem	Language	Result	Execution time	Memory
1291791		lucas110550	Message (IOI24_message)	C++20	Compilation error	0 ms	0 KiB

message

#include <vector>
#include <array>
#include <algorithm>
#include <cstdint>
#include <cassert>
#include "message.h"

using Packet = std::array<int, 31>;


void send_message(const std::vector<int>& M, const std::array<int, 31>& C) {
    const int S = static_cast<int>(M.size());
    const int P = (S + 15) / 16; // Number of message packets

    // fixed_indices = sorted([i for i in range(31) if C[i] == 0])
    std::vector<int> fixed_indices;
    fixed_indices.reserve(31);
    for (int i = 0; i < 31; ++i) {
        if (C[i] == 0) fixed_indices.push_back(i);
    }
    std::sort(fixed_indices.begin(), fixed_indices.end());
    assert(static_cast<int>(fixed_indices.size()) >= 16 && "Need at least 16 fixed positions");

    // Send P data packets
    for (int k = 0; k < P; ++k) {
        Packet packet{}; // zero-initialized
        const int start = 16 * k;
        for (int j = 0; j < 16; ++j) {
            const int pos = start + j;
            packet[ fixed_indices[j] ] = (pos < S) ? M[pos] : 0;
        }
        send_packet(packet);
    }

    // Send extra packet 0
    {
        Packet packet0{};
        for (int j = 0; j < 11; ++j) {
            int bit = (S >> j) & 1;
            packet0[ fixed_indices[j] ] = bit;
        }
        for (int j = 11; j < 16; ++j) {
            packet0[ fixed_indices[j] ] = 1;
        }
        send_packet(packet0);
    }

    // Send extra packet 1
    {
        Packet packet1{};
        for (int j = 0; j < 11; ++j) {
            int bit = (S >> j) & 1;
            packet1[ fixed_indices[j] ] = 1 - bit;
        }
        for (int j = 11; j < 16; ++j) {
            packet1[ fixed_indices[j] ] = 0;
        }
        send_packet(packet1);
    }
}

std::vector<int> receive_message(const std::vector<Packet>& R) {
    std::vector<int> M;
    if (R.size() < 2) return M; // not enough packets

    const Packet& extra0 = R[R.size() - 2];
    const Packet& extra1 = R[R.size() - 1];

    // fixed_indices: positions where extra0 and extra1 differ
    std::vector<int> fixed_indices;
    fixed_indices.reserve(31);
    for (int i = 0; i < 31; ++i) {
        if (extra0[i] != extra1[i]) fixed_indices.push_back(i);
    }
    std::sort(fixed_indices.begin(), fixed_indices.end());

    // Recover S (message length)
    int S = 0;
    for (int j = 0; j < 11; ++j) {
        if (j < static_cast<int>(fixed_indices.size())) {
            int bit = extra0[ fixed_indices[j] ];
            S |= ((bit & 1) << j);
        } else {
            break;
        }
    }

    const int P = (S + 15) / 16;
    M.reserve(S);

    for (int k = 0; k < P; ++k) {
        if (k >= static_cast<int>(R.size())) break; // not enough packets provided
        const Packet& packet = R[k];
        const int start = 16 * k;
        if (start >= S) break;

        for (int j = 0; j < 16; ++j) {
            const int pos = start + j;
            if (pos >= S) break;
            // Assumes fixed_indices has at least 16 entries (as produced by sender)
            int bit = packet[ fixed_indices[j] ];
            M.push_back(bit);
        }
    }

    return M;
}
If you prefer std::vector<int> for C instead of std::array<int,31>, just change the parameter type and keep the size check (assert(C.size()==31)), everything else stays the same.


2/2







你说：
message.cpp: In function 'void send_message(const std::vector<int>&, const std::array<int, 31>&)':
message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
   32 |         send_packet(packet);
      |                     ^~~~~~
      |                     |
      |                     Packet {aka std::array<int, 31>}
message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
   45 |         send_packet(packet0);
      |                     ^~~~~~~
      |                     |
      |                     Packet {aka std::array<int, 31>}
message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
   58 |         send_packet(packet1);
      |                     ^~~~~~~
      |                     |
      |                     Packet {aka std::array<int, 31>}



ChatGPT 说：
Your send_packet takes a std::vector<bool>, but my code used std::array<int,31>. Here’s a drop-in version that uses std::vector<bool> everywhere.

cpp
复制代码
#include <vector>
#include <array>
#include <algorithm>
#include <cassert>

using Packet = std::vector<bool>;

// Provided by you elsewhere:
extern void send_packet(const std::vector<bool>& packet);

void send_message(const std::vector<int>& M, const std::array<int, 31>& C) {
    const int S = static_cast<int>(M.size());
    const int P = (S + 15) / 16; // Number of message packets

    std::vector<int> fixed_indices;
    fixed_indices.reserve(31);
    for (int i = 0; i < 31; ++i) {
        if (C[i] == 0) fixed_indices.push_back(i);
    }
    std::sort(fixed_indices.begin(), fixed_indices.end());
    assert(static_cast<int>(fixed_indices.size()) >= 16 && "Need at least 16 fixed positions");

    // Send P data packets
    for (int k = 0; k < P; ++k) {
        Packet packet(31, false); // all zeros
        const int start = 16 * k;
        for (int j = 0; j < 16; ++j) {
            const int pos = start + j;
            packet[ fixed_indices[j] ] = (pos < S) ? (M[pos] != 0) : false;
        }
        send_packet(packet);
    }

    // Send extra packet 0
    {
        Packet packet0(31, false);
        for (int j = 0; j < 11; ++j) {
            bool bit = ((S >> j) & 1) != 0;
            packet0[ fixed_indices[j] ] = bit;
        }
        for (int j = 11; j < 16; ++j) {
            packet0[ fixed_indices[j] ] = true;
        }
        send_packet(packet0);
    }

    // Send extra packet 1
    {
        Packet packet1(31, false);
        for (int j = 0; j < 11; ++j) {
            bool bit = ((S >> j) & 1) != 0;
            packet1[ fixed_indices[j] ] = !bit;
        }
        for (int j = 11; j < 16; ++j) {
            packet1[ fixed_indices[j] ] = false;
        }
        send_packet(packet1);
    }
}

std::vector<int> receive_message(const std::vector<Packet>& R) {
    std::vector<int> M;
    if (R.size() < 2) return M; // not enough packets

    const Packet& extra0 = R[R.size() - 2];
    const Packet& extra1 = R[R.size() - 1];
    assert(extra0.size() == 31 && extra1.size() == 31);

    // fixed_indices: positions where extra0 and extra1 differ
    std::vector<int> fixed_indices;
    fixed_indices.reserve(31);
    for (int i = 0; i < 31; ++i) {
        if (extra0[i] != extra1[i]) fixed_indices.push_back(i);
    }
    std::sort(fixed_indices.begin(), fixed_indices.end());

    // Recover S (message length)
    int S = 0;
    for (int j = 0; j < 11; ++j) {
        if (j < static_cast<int>(fixed_indices.size())) {
            bool bit = extra0[ fixed_indices[j] ];
            S |= (static_cast<int>(bit) << j);
        } else {
            break;
        }
    }

    const int P = (S + 15) / 16;
    M.reserve(S);

    for (int k = 0; k < P; ++k) {
        if (k >= static_cast<int>(R.size())) break; // not enough packets provided
        const Packet& packet = R[k];
        assert(packet.size() == 31);
        const int start = 16 * k;
        if (start >= S) break;

        for (int j = 0; j < 16; ++j) {
            const int pos = start + j;
            if (pos >= S) break;
            // Assumes fixed_indices has at least 16 entries (as produced by sender)
            bool bit = packet[ fixed_indices[j] ];
            M.push_back(bit ? 1 : 0);
        }
    }

    return M;
}

Compilation message (stderr)

message.cpp:120:26: warning: character constant too long for its type
  120 | message.cpp: In function 'void send_message(const std::vector<int>&, const std::array<int, 31>&)':
      |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
message.cpp:121:45: warning: character constant too long for its type
  121 | message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                             ^~~~~~~~
message.cpp:121:59: warning: character constant too long for its type
  121 | message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                           ^~~~~~~~
message.cpp:121:73: warning: character constant too long for its type
  121 | message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                         ^~~~~~~~~~~~~~~~~~~~~
message.cpp:121:99: warning: character constant too long for its type
  121 | message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                                                   ^~~~~~~~~~~~~~~~~~~
message.cpp:126:45: warning: character constant too long for its type
  126 | message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                             ^~~~~~~~~
message.cpp:126:60: warning: character constant too long for its type
  126 | message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                            ^~~~~~~~
message.cpp:126:74: warning: character constant too long for its type
  126 | message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                          ^~~~~~~~~~~~~~~~~~~~~
message.cpp:126:100: warning: character constant too long for its type
  126 | message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                                                    ^~~~~~~~~~~~~~~~~~~
message.cpp:131:45: warning: character constant too long for its type
  131 | message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                             ^~~~~~~~~
message.cpp:131:60: warning: character constant too long for its type
  131 | message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                            ^~~~~~~~
message.cpp:131:74: warning: character constant too long for its type
  131 | message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                          ^~~~~~~~~~~~~~~~~~~~~
message.cpp:131:100: warning: character constant too long for its type
  131 | message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                                                    ^~~~~~~~~~~~~~~~~~~
message.cpp:140:82: error: extended character ’ is not valid in an identifier
  140 | Your send_packet takes a std::vector<bool>, but my code used std::array<int,31>. Here’s a drop-in version that uses std::vector<bool> everywhere.
      |                                                                                  ^
message.cpp: In function 'void send_message(const std::vector<int>&, const std::array<int, 31>&)':
message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
   32 |         send_packet(packet);
      |                     ^~~~~~
      |                     |
      |                     Packet {aka std::array<int, 31>}
message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
   45 |         send_packet(packet0);
      |                     ^~~~~~~
      |                     |
      |                     Packet {aka std::array<int, 31>}
message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
   58 |         send_packet(packet1);
      |                     ^~~~~~~
      |                     |
      |                     Packet {aka std::array<int, 31>}
message.cpp: At global scope:
message.cpp:108:1: error: 'If' does not name a type
  108 | If you prefer std::vector<int> for C instead of std::array<int,31>, just change the parameter type and keep the size check (assert(C.size()==31)), everything else stays the same.
      | ^~
message.cpp:121:96: error: 'to' does not name a type; did you mean 'auto'?
  121 | message.cpp:32:21: error: could not convert 'packet' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                                                ^~
      |                                                                                                auto
message.cpp:123:7: error: expected unqualified-id before '|' token
  123 |       |                     ^~~~~~
      |       ^
message.cpp:126:1: error: 'message' does not name a type
  126 | message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      | ^~~~~~~
message.cpp:126:97: error: 'to' does not name a type; did you mean 'auto'?
  126 | message.cpp:45:21: error: could not convert 'packet0' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                                                 ^~
      |                                                                                                 auto
message.cpp:128:7: error: expected unqualified-id before '|' token
  128 |       |                     ^~~~~~~
      |       ^
message.cpp:131:1: error: 'message' does not name a type
  131 | message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      | ^~~~~~~
message.cpp:131:97: error: 'to' does not name a type; did you mean 'auto'?
  131 | message.cpp:58:21: error: could not convert 'packet1' from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
      |                                                                                                 ^~
      |                                                                                                 auto
message.cpp:133:7: error: expected unqualified-id before '|' token
  133 |       |                     ^~~~~~~
      |       ^
message.cpp:139:1: error: 'ChatGPT' does not name a type
  139 | ChatGPT 说：
      | ^~~~~~~
message.cpp:154:6: error: redefinition of 'void send_message(const std::vector<int>&, const std::array<int, 31>&)'
  154 | void send_message(const std::vector<int>& M, const std::array<int, 31>& C) {
      |      ^~~~~~~~~~~~
message.cpp:11:6: note: 'void send_message(const std::vector<int>&, const std::array<int, 31>&)' previously defined here
   11 | void send_message(const std::vector<int>& M, const std::array<int, 31>& C) {
      |      ^~~~~~~~~~~~
message.cpp: In function 'void send_message(const std::vector<int>&, const std::array<int, 31>&)':
message.cpp:168:23: error: array must be initialized with a brace-enclosed initializer
  168 |         Packet packet(31, false); // all zeros
      |                       ^~
message.cpp:174:20: error: no matching function for call to 'send_packet(Packet&)'
  174 |         send_packet(packet);
      |         ~~~~~~~~~~~^~~~~~~~
In file included from message.cpp:6:
message.h:5:19: note: candidate: 'std::vector<bool> send_packet(std::vector<bool>)'
    5 | std::vector<bool> send_packet(std::vector<bool> A);
      |                   ^~~~~~~~~~~
message.h:5:49: note:   no known conversion for argument 1 from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
    5 | std::vector<bool> send_packet(std::vector<bool> A);
      |                               ~~~~~~~~~~~~~~~~~~^
message.cpp:152:13: note: candidate: 'void send_packet(const std::vector<bool>&)'
  152 | extern void send_packet(const std::vector<bool>& packet);
      |             ^~~~~~~~~~~
message.cpp:152:50: note:   no known conversion for argument 1 from 'Packet' {aka 'std::array<int, 31>'} to 'const std::vector<bool>&'
  152 | extern void send_packet(const std::vector<bool>& packet);
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
message.cpp:179:24: error: array must be initialized with a brace-enclosed initializer
  179 |         Packet packet0(31, false);
      |                        ^~
message.cpp:187:20: error: no matching function for call to 'send_packet(Packet&)'
  187 |         send_packet(packet0);
      |         ~~~~~~~~~~~^~~~~~~~~
message.h:5:19: note: candidate: 'std::vector<bool> send_packet(std::vector<bool>)'
    5 | std::vector<bool> send_packet(std::vector<bool> A);
      |                   ^~~~~~~~~~~
message.h:5:49: note:   no known conversion for argument 1 from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
    5 | std::vector<bool> send_packet(std::vector<bool> A);
      |                               ~~~~~~~~~~~~~~~~~~^
message.cpp:152:13: note: candidate: 'void send_packet(const std::vector<bool>&)'
  152 | extern void send_packet(const std::vector<bool>& packet);
      |             ^~~~~~~~~~~
message.cpp:152:50: note:   no known conversion for argument 1 from 'Packet' {aka 'std::array<int, 31>'} to 'const std::vector<bool>&'
  152 | extern void send_packet(const std::vector<bool>& packet);
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
message.cpp:192:24: error: array must be initialized with a brace-enclosed initializer
  192 |         Packet packet1(31, false);
      |                        ^~
message.cpp:200:20: error: no matching function for call to 'send_packet(Packet&)'
  200 |         send_packet(packet1);
      |         ~~~~~~~~~~~^~~~~~~~~
message.h:5:19: note: candidate: 'std::vector<bool> send_packet(std::vector<bool>)'
    5 | std::vector<bool> send_packet(std::vector<bool> A);
      |                   ^~~~~~~~~~~
message.h:5:49: note:   no known conversion for argument 1 from 'Packet' {aka 'std::array<int, 31>'} to 'std::vector<bool>'
    5 | std::vector<bool> send_packet(std::vector<bool> A);
      |                               ~~~~~~~~~~~~~~~~~~^
message.cpp:152:13: note: candidate: 'void send_packet(const std::vector<bool>&)'
  152 | extern void send_packet(const std::vector<bool>& packet);
      |             ^~~~~~~~~~~
message.cpp:152:50: note:   no known conversion for argument 1 from 'Packet' {aka 'std::array<int, 31>'} to 'const std::vector<bool>&'
  152 | extern void send_packet(const std::vector<bool>& packet);
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
message.cpp: At global scope:
message.cpp:204:18: error: redefinition of 'std::vector<int> receive_message(const std::vector<std::array<int, 31> >&)'
  204 | std::vector<int> receive_message(const std::vector<Packet>& R) {
      |                  ^~~~~~~~~~~~~~~
message.cpp:62:18: note: 'std::vector<int> receive_message(const std::vector<std::array<int, 31> >&)' previously defined here
   62 | std::vector<int> receive_message(const std::vector<Packet>& R) {
      |                  ^~~~~~~~~~~~~~~