CODEWITHSUNDEEP
c++rounding
NerdNet
NerdNet

Reputation: 439

round() function displaying scientific notation in c++

I'm writing a C++ code that divides two floats and outputs a whole number. but when I try dividing and rounding off using the round() function the number I get:

8878323 / 5 = 1.77566e+06

Every other number is being outputted as a whole number. Not sure why this one isn't.

code:

#include <iostream>
    #include <cmath>

using namespace std;

int main() {
    float a[30] = {41, 2733017,17473, 3164246, 105, 8015, 150, 12, 1090473, 81, 135, 15539, 8251, 7029, 9589930, 6027963, 5959834, 12661, -884988, 7258221, 8878323, 92, 1200422, 16645, -3062617, 147, 5421, 22, 9495996, 2302743};
    float b[30] = {2, 367, 506, 763, 14, 972, 12, 8, 889, 6, 10, 1840, 1294, 1834, 3822029, -1641686, 126, 1826, -2463550, 509, 5, 8, 717, 1270, 3789065, 14, 806, 4, 307, 803};
    
        
    float ans[30];    
    for(int i=0; i<30; i++) {
        ans[i] = a[i]/b[i];
        ans[i] = round(ans[i]);
    }
    
    for(int i=0; i<30; i++)
        cout << ans[i] << " ";
        
    return 0;    
}

Upvotes: 1

Views: 363

Answers (1)

selbie
selbie

Reputation: 104524

It's just a precision issue with cout. Pretty much any sufficiently large float will generate this issue.

Try this:

Add #include <iomanip> to the top of your program.

Then adjust your cout statement to use a setprecision specifier:

 cout << setprecision(15) << ans[i] << " ";

Alternatively, you could simply cast the result to a long before printing it

 cout << (long)(ans[i]) << " ";

Upvotes: 2

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