diff --git a/CMakeLists.txt b/CMakeLists.txt index 29b152c..1c859fe 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -7,3 +7,9 @@ if (NOT CMAKE_BUILD_TYPE) endif() add_executable(main main.cpp) + +if (MSVC) + target_compile_options(main PUBLIC /fp:fast /arch:AVX2) +else() + target_compile_options(main PUBLIC -ffast-math -march=native) +endif() \ No newline at end of file diff --git a/main.cpp b/main.cpp index cf6369b..4097d64 100644 --- a/main.cpp +++ b/main.cpp @@ -4,63 +4,73 @@ #include #include +constexpr size_t star_size = 48; +constexpr float G = 0.001; +constexpr float eps = 0.001; +constexpr float dt = 0.01; +constexpr float eps2 = eps * eps; +constexpr float Gdt = G * dt; + float frand() { return (float)rand() / RAND_MAX * 2 - 1; } +template struct Star { - float px, py, pz; - float vx, vy, vz; - float mass; + float px[N], py[N], pz[N]; + float vx[N], vy[N], vz[N]; + float mass[N]; }; -std::vector stars; +Star star; void init() { - for (int i = 0; i < 48; i++) { - stars.push_back({ - frand(), frand(), frand(), - frand(), frand(), frand(), - frand() + 1, - }); + for (int i = 0; i < star_size; i++) { + star.px[i] = frand(); + star.py[i] = frand(); + star.pz[i] = frand(); + star.vx[i] = frand(); + star.vy[i] = frand(); + star.vz[i] = frand(); + star.mass[i] = frand() + 1; } } -float G = 0.001; -float eps = 0.001; -float dt = 0.01; - void step() { - for (auto &star: stars) { - for (auto &other: stars) { - float dx = other.px - star.px; - float dy = other.py - star.py; - float dz = other.pz - star.pz; - float d2 = dx * dx + dy * dy + dz * dz + eps * eps; - d2 *= sqrt(d2); - star.vx += dx * other.mass * G * dt / d2; - star.vy += dy * other.mass * G * dt / d2; - star.vz += dz * other.mass * G * dt / d2; + for (size_t i = 0; i < star_size; ++i) { + float sumx = 0.0f, sumy = 0.0f, sumz = 0.0f; + for (size_t j = 0; j < star_size; ++j) { + float dx = star.px[j] - star.px[i]; + float dy = star.py[j] - star.py[i]; + float dz = star.pz[j] - star.pz[i]; + float d2 = dx * dx + dy * dy + dz * dz + eps2; + d2 *= std::sqrt(d2); + sumx += dx * star.mass[j] * Gdt / d2; + sumy += dy * star.mass[j] * Gdt / d2; + sumz += dz * star.mass[j] * Gdt / d2; } + star.vx[i] += sumx; + star.vy[i] += sumy; + star.vz[i] += sumz; } - for (auto &star: stars) { - star.px += star.vx * dt; - star.py += star.vy * dt; - star.pz += star.vz * dt; + for (size_t i = 0; i < star_size; ++i) { + star.px[i] += star.vx[i] * dt; + star.py[i] += star.vy[i] * dt; + star.pz[i] += star.vz[i] * dt; } } float calc() { float energy = 0; - for (auto &star: stars) { - float v2 = star.vx * star.vx + star.vy * star.vy + star.vz * star.vz; - energy += star.mass * v2 / 2; - for (auto &other: stars) { - float dx = other.px - star.px; - float dy = other.py - star.py; - float dz = other.pz - star.pz; - float d2 = dx * dx + dy * dy + dz * dz + eps * eps; - energy -= other.mass * star.mass * G / sqrt(d2) / 2; + for (size_t i = 0; i < star_size; ++i) { + float v2 = star.vx[i] * star.vx[i] + star.vy[i] * star.vy[i] + star.vz[i] * star.vz[i]; + energy += star.mass[i] * v2 / 2; + for (size_t j = 0; j < star_size; ++j) { + float dx = star.px[j] - star.px[i]; + float dy = star.py[j] - star.py[i]; + float dz = star.pz[j] - star.pz[i]; + float d2 = dx * dx + dy * dy + dz * dz + eps2; + energy -= star.mass[j] * star.mass[i] * G / std::sqrt(d2) / 2; } } return energy;