C++实现神经网络

C++实现神经网络（Neural Network）的代码实现可以非常复杂，不过幸好现在有许多高质量的库和工具可以帮助我们快速实现。下面是一个使用C++实现神经网络的例子。

首先，你需要安装一个C++机器学习库，比如说，TensorFlow、Caffe、Torch等。下面的例子使用的是TensorFlow。

#include "tensorflow/cc/ops/const_op.h"
#include "tensorflow/cc/ops/image_ops.h"
#include "tensorflow/cc/ops/standard_ops.h"
#include "tensorflow/core/framework/graph.pb.h"
#include "tensorflow/core/framework/tensor.h"
#include "tensorflow/core/graph/default_device.h"
#include "tensorflow/core/graph/graph_def_builder.h"
#include "tensorflow/core/lib/core/errors.h"
#include "tensorflow/core/lib/core/stringpiece.h"
#include "tensorflow/core/lib/core/threadpool.h"
#include "tensorflow/core/lib/io/path.h"
#include "tensorflow/core/lib/strings/stringprintf.h"
#include "tensorflow/core/platform/init_main.h"
#include "tensorflow/core/public/session.h"
#include "tensorflow/core/util/command_line_flags.h"

using namespace tensorflow;
using namespace tensorflow::ops;

int main(int argc, char* argv[]) {
  std::vector outputs;
  Scope root = Scope::NewRootScope();
  auto A = Const(root, { { 3.f, 3.f }, { 2.f, 2.f } });
  auto B = Const(root, { { 1.f, 1.f }, { -1.f, -1.f } });
  auto C = MatMul(root.WithOpName("C"), A, B);
  GraphDef graph;
  TF_CHECK_OK(root.ToGraphDef(&graph));

  std::unique_ptr session(NewSession(SessionOptions()));
  TF_CHECK_OK(session->Create(graph));
  TF_CHECK_OK(session->Run({}, {"C:0"}, {}, &outputs));

  LOG(INFO) << outputs[0].matrix();

  return 0;
}