text: #include "utils.h"
  
  const std::string kBoxRoot = "/var/local/lib/isolate";
  const std::string kTestdataRoot = "./testdata";
  
  std::string PadInt(int x, size_t width) {
    std::string ret = std::to_string(x);
    if (ret.size() < width) ret = std::string(width - ret.size(), '0') + ret;
    return ret;
  }
  
  std::string BoxPath(int box) {
    return kBoxRoot + '/' + std::to_string(box) + "/box/";
  }
  std::string BoxInput(int box) {
    return kBoxRoot + '/' + std::to_string(box) + "/box/input";
  }
  std::string BoxOutput(int box) {
    return kBoxRoot + '/' + std::to_string(box) + "/box/output";
  }
  std::string TdPath(int prob) {
    return kTestdataRoot + '/' + PadInt(prob, 4) + '/';
  }
  std::string TdMeta(int prob, int td) {
    return kTestdataRoot + '/' + PadInt(prob, 4) + "/input" + PadInt(td, 3) + ".meta";
  }
  std::string TdInput(int prob, int td) {
    return kTestdataRoot + '/' + PadInt(prob, 4) + "/input" + PadInt(td, 3);
  }
  std::string TdOutput(int prob, int td) {
    return kTestdataRoot + '/' + PadInt(prob, 4) + "/output" + PadInt(td, 3);
  }
  