Reaktor fast track outrun C++ solution

reaktor_outrun.cpp

// g++ -Ofast -fomit-frame-pointer -funroll-loops -o reaktor_outrun reaktor_outrun.cpp

#include <iostream>
#include <vector>
#include <algorithm>
#include <limits>
#include <cctype>
#include <cstdio>
int main(int argc, char** argv)
{
  std::vector<unsigned int> buffers[2];
  std::vector<unsigned int>* curr = &buffers[0];
  std::vector<unsigned int>* prev = &buffers[1];
  curr->reserve(100);
  prev->reserve(100);
  unsigned int k = 0;
  unsigned int i = 0;
  unsigned int v = 0;
  char c = '\0';
  bool inValue = false;
  std::FILE* file = std::fopen(argv[1], "r");
  
  // Ignore first line seed comment
  while(!std::feof(file) && std::getc(file) != '\n');
  
  int const BUF_SIZE = 1024 * 1024;
  char buf[BUF_SIZE] = {0};
  std::size_t bufCount = 1;
  std::size_t bufIndex = 0; 
  
  while(bufCount != 0)
  {
    bufCount = std::fread(buf, sizeof(buf[0]), BUF_SIZE, file);
    bufIndex = 0;
    while(bufIndex < bufCount)
    {
      c = buf[bufIndex];
      ++bufIndex;
      if(std::isdigit(c))
      {
        v = v * 10 + (c - '0');
        inValue = true;
        continue;
      }
      else if(!inValue)
      {
        continue;
      }
      
      if(i == k)
      {
        i = 0;
        k += 1;
        std::vector<unsigned int>* temp = prev;
        prev = curr;
        curr = temp;
        curr->push_back(0);
        prev->push_back(0);
      }
      
      if(k > 1)
      {
        if(i == 0)
        {
          v += prev->at(0);
        }
        else if(i == k - 1)
        {
          v += prev->at(k - 2);
        }
        else
        {
          v += prev->at(i) > prev->at(i - 1) ? prev->at(i) : prev->at(i - 1);
        }
      }
      curr->at(i) = v;
      ++i;
      v = 0;
      inValue = false;
    }
  }
  
  int max = *std::max_element(curr->begin(), curr->end());
  
  std::cout << max << std::endl;
  return 0;
}