oj.uz

Submission #1006240

# Submission time Handle Problem Language Result Execution time Memory
1006240 2024-06-23T15:13:16 Z AliMark71 Data Transfer (IOI19_transfer) C++17
100 / 100
 36 ms 2520 KB 
#include "transfer.h"

using namespace std;

std::vector<int> get_attachment(std::vector<int> source) {
    int xorSum = 0;
    for (int i = 0; i < source.size(); i++) if (source[i]) xorSum ^= (i + 1);
    
    int correctionSize = __builtin_popcount((int) source.size());
    
    vector<int> correctionData(correctionSize + 1);
    for (int i = 0; i < correctionSize; i++) if (xorSum&(1<<i)) correctionData[i] = 1;
    correctionData.back() = __builtin_popcount(xorSum) % 2;
    
    return correctionData;
}

std::vector<int> retrieve(std::vector<int> data) {
    int baseSize = (data.size() == 70 ? 6 : 8);
    
    vector<int> possibleSource(data.begin(), data.begin() + (1<<baseSize) - 1);
    vector<int> correctionData(data.begin() + possibleSource.size(), data.end());
    
    int correctionPopCount = 0;
    for (int i = 0; i < correctionData.size() - 1; i++) correctionPopCount += correctionData[i];
    
    if (correctionPopCount % 2 == correctionData.back()) {
        int checkSum = 0;
        for (int i = 0, val = 1; i < correctionData.size() - 1; i++, val *= 2) checkSum += correctionData[i] * val;
             
        int expectedCheckSum = 0;
        for (int i = 0; i < possibleSource.size(); i++) if (possibleSource[i]) expectedCheckSum ^= (i + 1);
        
        if (checkSum != expectedCheckSum) {
            int errorPos = checkSum ^ expectedCheckSum;
            possibleSource[errorPos - 1] ^= 1;
        }
    }

    return possibleSource;
}

Compilation message

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:7:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |     for (int i = 0; i < source.size(); i++) if (source[i]) xorSum ^= (i + 1);
      |                     ~~^~~~~~~~~~~~~~~
transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:25:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     for (int i = 0; i < correctionData.size() - 1; i++) correctionPopCount += correctionData[i];
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
transfer.cpp:29:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |         for (int i = 0, val = 1; i < correctionData.size() - 1; i++, val *= 2) checkSum += correctionData[i] * val;
      |                                  ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
transfer.cpp:32:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for (int i = 0; i < possibleSource.size(); i++) if (possibleSource[i]) expectedCheckSum ^= (i + 1);
      |                         ~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 792 KB Output is correct
2 Correct 1 ms 800 KB Output is correct
3 Correct 1 ms 800 KB Output is correct
4 Correct 2 ms 800 KB Output is correct
5 Correct 2 ms 788 KB Output is correct
6 Correct 1 ms 800 KB Output is correct
7 Correct 2 ms 792 KB Output is correct
8 Correct 2 ms 800 KB Output is correct
9 Correct 1 ms 800 KB Output is correct
10 Correct 1 ms 800 KB Output is correct
11 Correct 1 ms 880 KB Output is correct
12 Correct 1 ms 804 KB Output is correct
13 Correct 1 ms 812 KB Output is correct
14 Correct 1 ms 800 KB Output is correct
15 Correct 2 ms 792 KB Output is correct
16 Correct 1 ms 792 KB Output is correct
17 Correct 1 ms 800 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 2512 KB Output is correct
2 Correct 36 ms 2508 KB Output is correct
3 Correct 30 ms 2520 KB Output is correct
4 Correct 32 ms 2520 KB Output is correct
5 Correct 32 ms 2520 KB Output is correct
6 Correct 33 ms 2520 KB Output is correct
7 Correct 33 ms 2508 KB Output is correct
8 Correct 32 ms 2512 KB Output is correct
9 Correct 31 ms 2520 KB Output is correct
10 Correct 33 ms 2520 KB Output is correct
11 Correct 30 ms 2508 KB Output is correct
12 Correct 29 ms 2512 KB Output is correct
13 Correct 30 ms 2520 KB Output is correct
14 Correct 30 ms 2512 KB Output is correct
15 Correct 30 ms 2520 KB Output is correct
16 Correct 35 ms 2508 KB Output is correct
17 Correct 32 ms 2520 KB Output is correct
18 Correct 32 ms 2520 KB Output is correct
19 Correct 30 ms 2520 KB Output is correct