CODEWITHSUNDEEP
c++
zoite
zoite

Reputation: 189

Convert scientific notation to decimal

I'm trying to do the challenge on http://www.cstutoringcenter.com/problems/problems.php?id=2 and I'm having problems converting scientific notation to decimal notation, which I need to add the exponent together:

Here is my code so far:

#define FIRST 2
#define SECOND 20

#include <iostream>
#include <cmath>
#include <sstream>
#include <iomanip>

using namespace std;

int main()
{
    // Give variables initial setting
    int total = 0;
    float powanswer = 0;

    // Get rid of scientific notation for large numbers
    stringstream ss;
    ss.setf(ios::fixed);
    ss << pow(FIRST,SECOND);
    ss >> powanswer;


    // Output
    // Expected: 2^20 = 1048576 => 1+0+4+8+5+7+6 => 31
    // Outcome: 2^20 = 1.04858e+06  => 1+.+0+4+8+5+8+e+++0+6 => 32
    cout << FIRST << "^" << SECOND << " = " << powanswer << "  => ";


    // Convert power int to string
    string ResultText = "";
    stringstream convert;
    convert << powanswer;
    ResultText = convert.str();

    // Loop over total
    for (int x=0; x<ResultText.size(); x++)
    {

        // Convert character to integer
        int ResultNum = 0;
        stringstream convert;
        convert << ResultText[x];
        convert >> ResultNum;
        total+=ResultNum;

        // Output
        cout << ResultText[x];
        ResultText.size()-1 == x ? cout << " => " : cout << "+";

    }
    cout << total << endl;
    return 0;
}

I've tried searching everywhere on how to convert it, and I read I can use << fixed << on the stream, or .setf(ios::fixed) but neither seems to be working for me and I'm not sure what I'm doing wrong.

As marked in the code, here is the current output:

2^20 = 1.04858e+06  => 1+.+0+4+8+5+8+e+++0+6 => 32

What I want and expect to see is:

2^20 = 1048576 => 1+0+4+8+5+7+6 => 31

Edit: Spelling mistake

Upvotes: 1

Views: 3218

Answers (1)

Some programmer dude
Some programmer dude

Reputation: 409136

The variable powanswer is a float, but you want to print it as an integer?

How about something like:

int powanswer_int = (int) powanswer;
cout << FIRST << "^" << SECOND << " = " << powanswer_int << "  => ";

And use the powanswer_int later as well.

Upvotes: 3

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