Array with hex values in C++ - c++

Question

For the last day I have had some problems with this code. Here I want to upload with a .txt several hexadecimal values and if the sum of the first five numbers is equal to the last number, the code is correct.Then, the method main have to check if the rest methods were succeeded. But I don't know how do this, so I need your help...
#include <iostream>
#include <fstream>
#define FILECODE "file.txt"
#define N_CODE 6
using namespace std;
ifstream file;
void uploadCode(bool& exist, unsigned int longCode, unsigned int code[]);
bool IsValidCode(unsigned int code[]);
void main() {
unsigned int code[N_CODE];
bool exist;
unsigned int longCode=N_CODE;
IsValidCode(code);
if(IsValidCode(code)==true){
uploadCode(exist,longCode,code); //here I have the problem because I don't know how to call the method
cout << "SUCCESS" << endl;
}
else
cout << "FAIL" << endl;
}
void uploadCode(bool& exist, unsigned int longCode, unsigned int code[]) {
int i;
file.open(FILECODE);
if(file){
exist=true;
for(int i=0;i<longCode;i++){
file >> hex >> code[i];
cout << "Number " << i << ": "<< code[i] << endl;
}
cout << "EXIST" << endl;
}
else
cout << "NO EXIST" << endl;
exist=false;
file.close();
}
bool IsValidCode(unsigned int code[]) {
int i;
int sum=0;
for(int i=0; i<N_CODE-1; i++)
sum+=code[i];
cout << "Sum first five numbers: " << sum << endl;
if(sum==code[6])
return true;
else
return false;
return sum;
}

Answer 1

Here's a minimally modified version that does what you want. Of course, much better checks should be done on the return values of your input processing (i.e. - file >> hex >> code[i];) to see if those inputs are actually succeeding or not.
bool uploadCode(unsigned int longCode, unsigned int code[])
{
bool ret;
file.open(FILECODE); // TODO: no need for a global here; just use a locally constructed ifstream
if (file.good())
{
ret = true;
for(int i = 0; i < longCode; ++i)
{
file >> hex >> code[i];
cout << "Number " << i << ": "<< code[i] << endl;
}
cout << "EXIST" << endl;
}
else
{
ret = false;
cout << "NO EXIST" << endl;
}
file.close();
return ret;
}
int main()
{
unsigned int code[N_CODE];
if (!uploadCode(N_CODE, code))
{
cout << "File failure!" << endl;
return 1;
}
if (!IsValidCode(code))
{
cout << "Code failure!" << endl;
return 2;
}
cout << "SUCCESS" << endl;
return 0;
}

Answer 2

In your main function, you are calling IsValidCode twice before the data is read from the file. I don't think this is what you want.
A preferred method is:
Read first 6 numbers.
Sum the first 5 numbers.
If the sum != 6th number, return error status from main().
You don't need to make separate functions for each item above. Put them all in the main function. (The overhead to call and return from the simple functions may be more code than contained in the function.)
Edit 1: An example
int main(void)
{
const unsigned int CODE_LENGTH = 6;
ifstream input_file("file.txt");
if (!input_file)
{
cerr << "Error opening file.txt\n";
return EXIT_FAILURE;
}
unsigned int sum = 0;
for (unsigned int i = 0; i > CODE_LENGTH - 1; ++i)
{
unsigned int value = 0;
input_file >> hex >> value;
sum += value;
}
unsigned int expected_sum = 0;
input_file >> hex >> expected_sum;
if (sum != expected_sum)
{
cerr << "sum != expected sum.\n";
return EXIT_FAILURE;
}
// ....
return EXIT_SUCCESS;
}
Simple, no arrays necessary, no additional functions.