Question

Write a C++ function that (prints) the sum of the prime digits in an integer (unknown its number of digits)
e.g :
>> please enter an integer : 345693
3+5+3 = 11
>> please enter an integer : 76341237
7+3+1+2+3+7=23

Answer 1

#include <iostream>
#include <conio.h>
#include <string>

using namespace std;

bool IsPrime(int number)
{
if ((number & 1) == 0)
{
if (number == 2)
{
return true;
}
else
{
return false;
}
}
for (int i = 3; (i * i) <= number; i += 2)
{
if ((number % i) == 0)
{
return false;
}
}
return number != 1;
}

int main()
{
string number="";
cout<<"Please enter an integer : ";
getline(cin,number);
int sum=0;
for(int i=0;i<number.length();i++){
int k=int(number[i])- '0';
if(IsPrime(k)==true){
sum+=k;
cout<<number[i]<<"+";
}
}
cout<<" = "<<sum;
getch();
return 0;
}