vectors to functions, bool key search help!!!

[sesslit805]

WE'RE SUPPOSED TO DO THE FOLLOWING (THIS WAS MY LAB FOR LAST WEEK AND IM NOT UNDERSTANDING IT. NOT SURE IF I SHOULD CONSIDER DROPPING MY MAJOR BUT ITS HARD FOR ME TO GRAB ONTO THE CONCEPT) I REALLY NEED HELP AND EXPLANATIONS PLEASE! I HATE ASKING FOR HELP BECAUSE I FEEL THAT I BUGG TO MUCH. FOUND THIS FORUM AND REALLY THINK THIS IS AWESOME PLEASE HELP ME !
MY CODE IS A MESS !!

I KNOW THIS IS SUPPOSED TO BE EASY BUT ITS NOT FOR ME.

Write a program that reads an unknown number of integers from a data file called “data.txt” into a vector of integers named V. V is initially empty and grows as the user reads data from file.

Once done copying data into vector V, you need to print the contents of V (write a function print that prints the contents of a vector of any size) and perform some other tasks on the vector as described below.

Your program should do the following:
1. Create an empty vector of integers V.
2. Read the integers from data.txt into V. Print its contents. You may assume data.txt contains the following numbers:

5 6 12 87 100 28 35 66 77 29

3. Remove the last element from the vector.
6. Ask the user to input a key. Then search for the key in vector V and inform the user about the existence (true / false) of the key in V.

  #include <iostream>
#include <vector>
#include <fstream>

using namespace std;

void print( vector<int>);
void Keysearch(vector<int>);

int main()
{
  vector <int> v;
  int count;
  int key;
  bool exist = false;
  int tmp;
  ifstream inputFile;
  inputFile.open("data3.txt");

  exist = Keysearch (v)
    if(!inputFile)
      {

        cout << "File does not exist";
      }

    else
      {


        while (inputFile >> count)

          {
            //print (v);                                                                                                                                                             

                cout << count <<" ";
                v.push_back(count) ;

          }
        cout << endl;
        inputFile.close();
      }


    v.pop_back();

    for(int val:v)

        cout << val;

    return 0;

}
    void print (vector<int> v)
    {



    }

bool Keysearch()
{
  int key;
  cout << "Please enter a key: " << endl;
  cin >> key;

  for (int i =0; i < key ==true; i++)
    {
      if (key== vector <int> v)
        key == true;
      else key == false;
    }

[Hengry]

// Give your vector a name.
void print( vector<int>); 
void Keysearch(vector<int>);

bool Keysearch() // Missing parameter
{
  int key;
  cout << "Please enter a key: " << endl;
  cin >> key;

  // For loop is incorrect. The loop should just iterate through the vector
  // Finding the key should be done inside the loop
  for (int i =0; i < key ==true; i++)
    {
      if (key== vector <int> v) // Should be: key == v.at(i);
        key == true; // Should be "return true;", since it's a bool.
      else key == false; // I presume you meant "return false;", but it's still incorrect
    }
// return false should be AFTER the whole for loop, because if it's inside the loop
// the loop compares the first integer and if it is not the key, it would do an early stop
// If "return false" is after the loop, it'll return false after iterating through whole loop 

[Mantorr22]

The following code solves your assignment. It might be fairly easy if you learn C++ enough.

#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
	int number;
	std::string str;
	std::stringstream ss;
	std::vector<int> numbers;

	std::ifstream inFile("data.txt");

	// Check if the file is open
	if(!inFile.is_open())
	{
		std::cerr << "The file data.txt could not be opened. Please try again." << std::endl;
		std::cin.get(); 
		return 1;
	}

	// One way to input the numbers into the vector
	while(inFile >> str)
	{
		ss << str;
		ss >> number;

		numbers.push_back(number);

		ss.str("");
		ss.clear();
	}

	// Print out the vector contents
	std::cout << "The vector loaded with " << numbers.size() << " element(s). " << std::endl;

	if("Print_out_vector_contents")
	{
		std::cout << "  ";
		for(std::vector<int>::iterator it = numbers.begin(); it != numbers.end(); it++)
		{
			std::cout << *it;
			if((it + 1) != numbers.end()) std::cout << ", ";
		}		
	}

	// Remove the last element from the vector
	numbers.erase(numbers.end() - 1);

	// Ask the user to input a key to inform the existence of the key in the vector
	int key = -(int)(0xFFFF);

	std::cout << std::endl;
	std::cout << "Enter a key : "; std::cin >> key;

	std::vector<int>::iterator it = std::find(numbers.begin(), numbers.end(), key);

	if(it != numbers.end()) 
	{
		std::cout << "Existence : true" << std::endl; 
	}
	else 
	{
		std::cout << "Existence : false" << std::endl;
	}

	std::cin.ignore();
	std::cin.get();

	return 0;
}