NoZeros

#include <vector>
#include <cstdlib>
#include <algorithm>
#include <iostream>
#include <sys/time.h>                // for gettimeofday()
//#include <cstdint> C++11 Standart only
using namespace std;

void nozero (std::vector<long long> &v)
{
  long long left_val(*v.begin()), cur_val(*v.begin());
  for (std::vector<long long>::iterator i = v.begin(); i != v.end(); ++i)
  {
    cur_val = *i;
    if (cur_val) left_val = cur_val; else *i = left_val;
  }
}

void nozeroN (std::vector<long long> &v, int N)
{
  long long left_val(*v.begin()), cur_val(*v.begin());
  int n(N);
  for (std::vector<long long>::iterator i = v.begin(); i != v.end(); ++i)
  {
    cur_val = *i;
    if (cur_val) 
    {
      left_val = cur_val;
      n = N;
    }
    else 
    {
      if (n) 
      {
        *i = left_val;
        --n;
      }
    }
  }
}

int main()
{
  timeval t1, t2;
  double elapsedTime;
  std::vector<long long> v(100000000); // vector for 100000000 elements
  std::generate(v.begin(), v.end(), rand); // filling with random numbers
  // start timer
  gettimeofday(&t1, NULL);
  nozero(v);
  // stop timer
  gettimeofday(&t2, NULL);
  // compute and print the elapsed time in millisec
  elapsedTime = (t2.tv_sec - t1.tv_sec) * 1000.0;      // sec to ms
  elapsedTime += (t2.tv_usec - t1.tv_usec) / 1000.0;   // us to ms
  std::cout << "nozero -> " << elapsedTime << " ms.\n";
  for (std::vector<long long>::iterator i = v.begin(); i != v.end(); ++i)
  {
    if (*i == 0)
    {
      std::cout << "v[" << std::distance(v.begin(), i) << "] = " << (*i) << "\n";
    }
  }
  std::generate(v.begin(), v.end(), rand); // filling with random numbers
  int N(3); // number of zeros for changing
  // start timer
  gettimeofday(&t1, NULL);
  nozeroN(v, N);
  // stop timer
  gettimeofday(&t2, NULL);
  // compute and print the elapsed time in millisec
  elapsedTime = (t2.tv_sec - t1.tv_sec) * 1000.0;      // sec to ms
  elapsedTime += (t2.tv_usec - t1.tv_usec) / 1000.0;   // us to ms
  std::cout << "nozeroN -> " << elapsedTime << " ms.\n";
  return 0;
}