C++ to Python Sample

test.cpp

#include <cstdio>
#include <fstream>
#include <random>
#include <string>
#include <vector>

const int L = 64;
const int N = L * L;

std::vector<int> spins(L *L);

void init() {
  std::mt19937 mt;
  std::uniform_int_distribution<> ud(0, 1);
  for (int i = 0; i < N; i++) {
    int r = ud(mt);
    spins[i] = r * 2 - 1;
  }
}

void save_data(const std::string filename) {
  std::ofstream ofs(filename, std::ios::binary);
  ofs.write((char *)spins.data(), spins.size() * sizeof(int));
}

int main() {
  init();
  save_data("test.dat");
}

test.py

from PIL import Image, ImageDraw
import numpy as np

with open("test.dat", "rb") as f:
    data = f.read()
spins = np.frombuffer(data, dtype='<i')

L = 64
g = 4
im = Image.new("RGB", (L*g, L*g), "white")
draw = ImageDraw.Draw(im)

color = "black"
for x in range(L):
    for y in range(L):
        i = x + y*L
        if spins[i] == 1:
            color = "black"
        else:
            color = "white"
        draw.rectangle((x*g, y*g, x*g+g, y*g+g), fill=color)


im.save("test.png")

以下を実行すると

g++ test.cpp
./a.out
python test.py

test.pngができます。