Если слово начинается с гласной буквы

#include <algorithm>
#include <fstream>
#include <iterator>
#include <string>
 
int main()
{
    std::copy_if(std::istream_iterator<std::string>(std::ifstream("input.txt")), std::istream_iterator<std::string>(), std::ostream_iterator<std::string>(std::ofstream("output.txt"), " "), [](const std::string &s) { return s.find_first_of("aeiouy") == 0; });
}

#include <stdio.h>
#include <string.h>
#include <windows.h>
 
 
int main()
{
 
SetConsoleCP(1251);
SetConsoleOutputCP(1251);
 
   char* fname="input.txt";
   char t[1024],*y;
 
   FILE *r;
   r = fopen(fname, "r");
   fgets(t,1024,r);
 
   printf("\nСчитывание данных\n");
   printf("\n%s",t);
 
   y=strtok(t, " ,.");
   while(y != NULL) {
      if(y[0] == 'e' || y[0] == 'i' ||
      y[0] == 'o' || y[0] == 'u' ||
      y[0] == 'y' || y[0] == 'a' ||
      y[0] == 'E' || y[0] == 'I' ||
      y[0] == 'O' || y[0] == 'U' ||
      y[0] == 'Y' || y[0] == 'A') {
         printf("\nС гласной = %s",y);
      }
      y=strtok (NULL, " ,.");
   }
 
   return 0;
}

#ifndef _HEADER_H_
#define _HEADER_H_
#include <iostream>
 
void CopyWordsWithFirstVowel(std::istream &in, std::ostream &out);
 
#endif

#include <algorithm>
#include <iterator>
#include <string>
#include "func.h"
 
void CopyWordsWithFirstVowel(std::istream &in, std::ostream &out)
{
    std::copy_if(std::istream_iterator<std::string>(in), std::istream_iterator<std::string>(), std::ostream_iterator<std::string>(out, " "), [](const std::string &s) { return s.find_first_of("aeiouy") == 0; });
}

#include <fstream>
#include "func.h"
 
int main()
{
    CopyWordsWithFirstVowel(std::ifstream("input.txt"), std::ofstream("output.txt"));
}