情報数学概論だったり？

LightsOut.cpp

#include <iostream>
#include <vector>
#include <algorithm>
#include <mutex>

typedef int64_t table;
const int SIZE = 5;
const table BASE = 1;
const table N_BASE = -1;
const table NUMBER_OF_PATTERN = BASE << (SIZE * SIZE);
const table TABLE_MASK = ~(N_BASE << (SIZE * SIZE));
table RIGHT_MASK = 0;
table LEFT_MASK = 0;
table TOP_MASK = 0;
table BOTTOM_MASK = 0;

std::vector<table> results;
std::mutex mtx;

bool validate(table p) {
  table table = TABLE_MASK;
  table ^= p;
  table ^= (p >> 1) & (~LEFT_MASK);
  table ^= (p << 1) & (~RIGHT_MASK);
  table ^= p << SIZE;
  table ^= p >> SIZE;
  return (table & TABLE_MASK) == 0;
}

int main() {
  for (int i = 0; i < SIZE; i++) {
    RIGHT_MASK |= BASE << (i * SIZE);
    LEFT_MASK |= (BASE << (SIZE - 1)) << (i * SIZE);
    TOP_MASK |= (BASE << i) << (SIZE * (SIZE - 1));
    BOTTOM_MASK |= BASE << i;
  }
#pragma omp parallel for
  for (table i = 0; i < NUMBER_OF_PATTERN; i++) {
    if (validate(i)) {
#ifdef _OPENMP
      mtx.lock();
#endif
      results.push_back(i);
#ifdef _OPENMP
      mtx.unlock();
#endif
    }
  }
  std::for_each(results.begin(), results.end(), [](table r)
  {
    for (int i = SIZE - 1; i >= 0; i--) {
      for (int j = SIZE - 1; j >= 0; j--) {
        if ((r & (BASE << (i * SIZE + j))) == 0)
          std::cout << "0";
        else
          std::cout << "1";
      }
      std::cout << std::endl;
    }
    std::cout << std::endl;
  });
  return 0;
}