Unexpected decrementation of result

[SOURABH PRAKASH PATI]

the following code takes in any number as input.Then re-forms the same number digit by digit and (should) produces the same number as output.But due to some reason the value of the number reduces by 1 after every third itteration of the loop.Can someone please expain why this is happening...(for eg-- 123 is becoming 122 and similarly 123456 is becoming 123454 (why ?)...Here is my code

<code>
#include<iostream>
#include<math.h>
using namespace std;
int main()
{
int inp;
cout<<"\n ENTER NUMBER :\t";cin>>inp;
int num=inp,digi_num=0,i=0;
while(inp>0)
{
digi_num+=(pow(10,i))*(inp%10);
inp=inp/10;
i++;
}
cout<<"\n"<<digi_num;
return 0;
}
</code>

[helios]

It works for me.

ENTER NUMBER : 123

123

[JLBorges]

> But due to some reason the value of the number reduces by 1

The function std::pow() performs a computation on floating point values and yields a floating point value as the result. If getting a guaranteed exact integer result is important, do not use floating point operations.

#include <iostream>

int main()
{
    unsigned int number ;
    std::cout << "enter number :\t";
    std::cin >> number ;

    unsigned int digi_num = 0 ;

    for( unsigned int pow10 = 1 ; number > 0 ; pow10 *= 10 )
    {
        digi_num += pow10 * (number%10) ;
        number /= 10 ;
    }

    std::cout << digi_num << '\n' ;
}