How do i take integers from a file and place them in an int vector?

Question

I am trying to take a text file and take the integers inside the file and transfer them into a vector in which can be read into different functions.

This is what i have so far:

int main(int argc, char *argv[] )
{
vector<int> buff;
argv[1] = "input_24_0.txt";

if (argc < 2)
{
    std::cout << "usage: " << argv[0] << " <filename>\n";
    return 2;
}
std::ifstream fin(argv[1]);
if (fin)
{
    std::stringstream ss;
    // this copies the entire contents of the file into the string stream
    ss << fin.rdbuf();
    // get the string out of the string stream
    std::string contents = ss.str();
    std::cout << contents;
    // construct the vector from the string.
    std::vector<int> buff(contents.begin(), contents.end());
}
else 
{
    std::cout << "Couldn't open " << argv[1] << "\n";
    return 1;
}

clock_t t1, t2, t3, t4;

int maxSum;

t1 = clock();
maxSum = maxSubSum1(buff);
cout << "MaxSubSum1 is " <<  maxSum << endl;
cout << double( clock() - t1 )
/ (double)CLOCKS_PER_SEC<< " seconds." << endl;
t1 = clock() - t1;

t2 = clock();
maxSum = maxSubSum2( buff );
cout << "MaxSubSum2 is " <<  maxSum << endl;
cout << double( clock() - t2)
/ (double)CLOCKS_PER_SEC<< " seconds." << endl;
t2 = clock() - t2;

t3 = clock();
maxSum = maxSubSum3(buff );
cout << "MaxSubSum3 is " <<  maxSum << endl;
cout << double( clock() - t3 )
/ (double)CLOCKS_PER_SEC<< " seconds." << endl;
t3 = clock() - t3;

t4 = clock();
maxSum = maxSubSum4( buff );
cout << "MaxSubSum4 is " <<  maxSum << endl;
cout << double( clock() - t4 )
/ (double)CLOCKS_PER_SEC<< " seconds." << endl;
t4 = clock() - t4;

system("pause");

return 0;
 }

NG:**argv[1] = "input_24_0.txt";**,Local redifine?:std::vector buff(contents.begin(), contents.end()); — BLUEPIXY, Oct 05 '11 at 11:49

score 0 · Answer 1 · 2011-10-05T02:56:55.387

0

If the numbers in the file are separated by whitespace, you could do the following:

 std::ifstream iStream;
 iStream.open("filename.ext");
 int tempVariable;

 if (iStream) {
   while (iStream >> tempVariable) {
      // Any routines to check the value of the number if necessary
      vector.push_back(tempVariable);
   }
   iStream.close();
 }
 else
   // Error routine

If the numbers are not separated by whitespace, you can use your string stream approach, and loop through the stream converting each char into it's decimal value.

edited Oct 05 '11 at 02:56

answered Oct 05 '11 at 02:46

Sorry.. I was trying to provide a snippet of how the code might look. Obviously you would declare an int variable that you would put values in one at a time, do any necessary checking of the value read from the file, then store it in the vector. – Oct 05 '11 at 02:55
ya i declared the tempVariable to an int. i assumed. And it doesnt take any routines all it does it put all the ints into a vector so i can use the vector in the arguments in the other functions for my program. – user977154 Oct 05 '11 at 03:06
Then the code sample above placed in your main() function will work assuming the values are separated by whitespace (space, tab, line break, etc). – Oct 05 '11 at 03:11
My functions take in these parameters:int maxSubSum4(const vector & a); – user977154 Oct 05 '11 at 03:42
Change the parameter to maxSubSum4(vector& a); Remove the 'const' keyword. Const makes it read-only. – Oct 05 '11 at 04:02

How do i take integers from a file and place them in an int vector?

1 Answers1