Adding all numbers from string - c++

Question

I'm trying to add all numbers from string, but I can't figure out how do I add a 2 digit number.
ex: ab32d3
I want the answer to be 35.
This is my code:
int main()
{
int max=0,min=100000,sum=0,totalsum=0;
string s;
ifstream in ("Unos.txt");
while(getline(in,s))
{
cout<<s<<endl;
for(int i=0;i<s.length();++i)
{
if(s[i]>max)
{
max=s[i]-'0';
}
if(s[i]<min)
{
min=s[i]-'0';
}
if(isdigit(s[i]))
{
sum=10*sum+s[i]-'0';
}
else
{
totalsum+=sum;
sum=0;
}
}
}
totalsum+=sum;
cout<<"Najveci broj je: "<<max<<endl;
cout<<"Najmanji broj je: "<<min<<endl;
cout<<"Zbir svih brojeva je: "<<totalsum<<endl;
return 0;
}

Answer 1

Try this:
#include <iostream>
#include <string>
#include <cctype>
using namespace std;
int main() {
string str = "ab32d3", temp;
int sum = 0;
for ( int i = 0; i < str.size(); i++ ) {
if ( isdigit(str[i]) ) temp.push_back(str[i]);
else {
if ( temp.size() > 0 ) {
sum += stoi(temp);
temp = string();
}
}
}
// Last number (if exists)
if ( temp.size() > 0 ) sum += stoi(temp);
cout << sum << endl;
return 0;
}
It will print 35

Answer 2

#include <iostream>
#include <cctype>
int main() {
std::string s = "ab32d3";
int value_so_far = 0;
int total = 0;
for (int i = 0; i < s.length(); ++i)
{
if (isdigit(s[i])) { // This keeps a running total until the number ends
value_so_far = 10 * value_so_far + s[i] - '0';
} else { // Here the number has ended - Add to the total and reset
total += value_so_far;
value_so_far = 0;
}
}
// Got to the end - Add what is left!
total += value_so_far;
std::cout << "Ans:" << total << std::endl;
// your code goes here
return 0;
}
Here is the link: ideone code.
Please check the comments in the code as to the explanation.