parsing - extracting digits from input string c++ -

i'm trying parsing input string reactions read file @ formula :2w+b=8a+10z, i'm not interested in characters need split , extract integer values put them in vector i.e vector associated reaction here :[2 1 8 10] thought many things: std::strtok(),isdigital(),find_first_of() didn't work integer values ... can body ??

here try:

int main() {   std::string input;   std::getline(std::cin, input);   std::stringstream stream(input);   while(1) {       int n;       stream >> n;       char * pch;       pch = strtok (input," ");       while (pch != null)         {           printf ("%s\n",pch);           pch = strtok (null, " ,.");         }   } } 

you this, comments see code

#include <iostream> #include <string> #include <vector>  std::vector<int> split(std::string str) {   std::vector<int> result; // contain different ints    // set pointer first character in string   char const* pch = str.c_str();   std::string digit; // buffer keep digits if more 1   int sign = 1; // each number has sign -1 or 1    (; *pch; ++pch)   {     if (std::isdigit(*pch))  // if digit, put in temp buffer     {       digit += *pch;     }     else if (std::isalpha(*pch)) // if not digit evaluate ones have     {       if (digit.empty()) // none assume 1 before letter e.g. w+2b       {         result.push_back(1*sign);       }       else        {         result.push_back(stoi(digit)*sign);         digit = "";       }     }     else  // determine sign of number     {       digit = "";       if (*pch == '+')        {         sign = 1;        }       else if (*pch == '-')        {         sign = -1;       }     }   }    return result; }   int main() {   using namespace std;    string expr{"-2w+b=-8a+10z"};   auto digits = split(expr);   (auto& digit : digits)   {     cout << digit << endl;   }     return 0; }