Different outputs in online gdb compiler and vs code

Question

code--

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    int x, a, b, c = 0;
    cout << "Enter the number" << endl;
    cin >> x;
    for (int i = 0; i <= 7; i++)
    {
        a = pow(10, I);
        b = 10 * ((x % a) - c) / a;
        cout << b;
        c = x % a;
    }
}

The code is written to reverse the numbers but for 1024 vs code shows 04301000 and onlinegdb shows 04201000.

you say that the code is supposed to reverse the numbers. For 1024 is the expected output 4201? — yem, Jun 02 '22 at 05:24
The float-taking and float returning `pow()` function is risky for integer handling. It can easily cause unreliable results, because floats are broken for integer things, as you probably know. — Yunnosch, Jun 02 '22 at 05:49
https://stackoverflow.com/questions/16923249/unusual-output-from-pow https://stackoverflow.com/questions/56522223/pow-function-giving-wrong-answer — Yunnosch, Jun 02 '22 at 05:51
the expected output was the one shown by onlinegdb compiler. — FlyingDoDo, Jun 02 '22 at 06:23
i took 7 as a random integer so that upto 7 digits number gets reversed. — FlyingDoDo, Jun 02 '22 at 06:24
If the pow() function is unreliable what else can I use for exponential function. — FlyingDoDo, Jun 02 '22 at 06:27
Implement your own pow function or simply use a for loop to find power. — kiner_shah, Jun 02 '22 at 06:30
Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. — Community, Jun 03 '22 at 08:05

score 0 · Answer 1 · answered Jun 02 '22 at 14:11

You don't even need pow:

#include <iostream>

int main()
{
    unsigned int x = 0, y = 0;
    std::cout << "Enter the number: ";
    std::cin >> x;
    while (x > 0) {
        y = 10 * y + (x % 10);
        x /= 10;
    }
    std::cout << y << std::endl;
}

Or if you don't want to remember the result and just print it, like the original:

#include <iostream>

int main()
{
    unsigned int x = 0;
    std::cout << "Enter the number: ";
    std::cin >> x;
    while (x > 0) {
        std::cout << x % 10;
        x /= 10;
    }
    std::cout << std::endl;
}

Thanks but my main concern was why is the output different in VS code and onlinegdb compiler. — FlyingDoDo, Jun 04 '22 at 12:16

Different outputs in online gdb compiler and vs code

1 Answers1