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How do I convert an integer into digits and add their sum?

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Join Date: Apr 2008

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ivailosp

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Re: How do I convert an integer into digits and add their sum?

#11

Sep 29th, 2008

 Help with Code Tags 
 cpp Syntax (Toggle Plain Text) 
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
 
void print_int(int number){
	stringstream tmp_stream;
	tmp_stream << number;
	string str_num(tmp_stream.str());
	int sum = 0;
	for (size_t i = 0; i < str_num.size(); ++i){
		cout << str_num[i] << ' ';
		sum+=str_num[i]-'0';
	}
	cout << sum;
}
 
int main(int argc, char **argv) {
	int number;
	cin >> number;
	print_int(number);
	return 0;
}
#include <iostream>
#include <sstream>
#include <string>
using namespace std;

void print_int(int number){
	stringstream tmp_stream;
	tmp_stream << number;
	string str_num(tmp_stream.str());
	int sum = 0;
	for (size_t i = 0; i < str_num.size(); ++i){
		cout << str_num[i] << ' ';
		sum+=str_num[i]-'0';
	}
	cout << sum;
}

int main(int argc, char **argv) {
	int number;
	cin >> number;
	print_int(number);
	return 0;
}

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Join Date: Sep 2008

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Re: How do I convert an integer into digits and add their sum?

#12

Sep 29th, 2008

Thanks again. One of the problems I did counted as a bonus and was actually worth more than this problem. I understand the solution now, and even though I didn't answer correctly I still scored a 100 because of the bonus question

Thanks!

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Re: How do I convert an integer into digits and add their sum?

#13

Sep 30th, 2008

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Originally Posted by ivailosp

Help with Code Tags

cpp Syntax (Toggle Plain Text)
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
 
void print_int(int number){
	stringstream tmp_stream;
	tmp_stream << number;
	string str_num(tmp_stream.str());
	int sum = 0;
	for (size_t i = 0; i < str_num.size(); ++i){
		cout << str_num[i] << ' ';
		sum+=str_num[i]-'0';
	}
	cout << sum;
}
 
int main(int argc, char **argv) {
	int number;
	cin >> number;
	print_int(number);
	return 0;
}
#include <iostream> #include <sstream> #include <string> using namespace std; void print_int(int number){ stringstream tmp_stream; tmp_stream << number; string str_num(tmp_stream.str()); int sum = 0; for (size_t i = 0; i < str_num.size(); ++i){ cout << str_num[i] << ' '; sum+=str_num[i]-'0'; } cout << sum; } int main(int argc, char **argv) { int number; cin >> number; print_int(number); return 0; }

Interesting to see the different solution..heres the one i used, note this is just function not main program to call it

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <cmath>
#include <limits.h>
#include "DigitSeparator.h"
 
void DigitSeparator::Separator( long int x ){
     int z;
     int q = 1;
     int sum = 0;
 
     if(x <= ULONG_MAX){
         while(1){
             if(x < pow(10.0, q++)){
                 z = q-1;
                 break;
                 }
             }            
         while (z != 0) sum += (int)((x%(int)(pow(10.0, z)+0.5))/pow(10.0, --z));
         std::cout << sum;
     }
     std::cin.clear();
     std::cout << "\n\n";
}
#include <iostream>
#include <cmath>
#include <limits.h>
#include "DigitSeparator.h"

void DigitSeparator::Separator( long int x ){
     int z;
     int q = 1;
     int sum = 0;
     
     if(x <= ULONG_MAX){
         while(1){
             if(x < pow(10.0, q++)){
                 z = q-1;
                 break;
                 }
             }            
         while (z != 0) sum += (int)((x%(int)(pow(10.0, z)+0.5))/pow(10.0, --z));
         std::cout << sum;
     }
     std::cin.clear();
     std::cout << "\n\n";
}

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Re: How do I convert an integer into digits and add their sum?

#14

Sep 30th, 2008

Since we're now giving out alternative solutions, here's mine:

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream>
#include <iterator>
 
template <typename OutIt>
int sum_digits ( int value, int radix, OutIt *it = 0 )
{
  if ( value == 0 )
    return 0;
 
  int digit = value % radix;
  int sum = sum_digits ( value / radix, radix, it ) + digit;
 
  if ( it != 0 )
    *it++ = digit;
 
  return sum;
}
 
int main()
{
  std::cout<<"Enter an integer: ";
 
  int value;
 
  if ( std::cin>> value ) {
    int sum = sum_digits ( value, 10, 
      &std::ostream_iterator<int> ( std::cout, " " ) );
 
    std::cout<<"\nThe sum is "<< sum <<'\n';
  }
}
#include <iostream>
#include <iterator>

template <typename OutIt>
int sum_digits ( int value, int radix, OutIt *it = 0 )
{
  if ( value == 0 )
    return 0;

  int digit = value % radix;
  int sum = sum_digits ( value / radix, radix, it ) + digit;

  if ( it != 0 )
    *it++ = digit;

  return sum;
}

int main()
{
  std::cout<<"Enter an integer: ";

  int value;

  if ( std::cin>> value ) {
    int sum = sum_digits ( value, 10, 
      &std::ostream_iterator<int> ( std::cout, " " ) );

    std::cout<<"\nThe sum is "<< sum <<'\n';
  }
}