c++ - problems with dividing the words while parsing the formatted input -

#include <iostream> #include <sstream> #include <fstream> #include <vector> #include <string> int main(int argc, char *argv[]) {     std::vector<std::string> vec;     std::string line;     std::ifstream in(argv[1]);     while(!in.eof()) {         std::getline(in,line);         vec.push_back(line);     }     std::istringstream is;     line = "";     for(auto a:vec) {         for(auto = a.begin(); != a.end(); i++) {             if(!(isspace(*i) | ispunct(*i)))                 line += *i;             else {                 is.str(line);                 std::cout << is.str() << std::endl;                 line = "";             }         }     }     std::cout << is.str() << std::endl;     return 0; } 

i've written program takes file , puts each line in vector of strings. reads 1 word @ time element.

when i'm reading vector having trouble specifying new lines. output concatenates end of 1 line , beginning of next. how can specify there new line?

the file content i'm reading:

math 3 2 math 4 3 math 5 4 phys 3 1 math 3 1 comp 3 2 

the output i'm getting:

math 3 2math 4 3math 5 4phys 3 1math 3 1comp 3 3 

edit::

to clarify, vector elements constructed correctly. if print in for(auto a:vec), give me line line file. it's when try build word each char in vector. asking can specify there new line

line += a[i]  

does not keep adding line when hits end of 1 line.

don't do

while (!in.eof()) { ... } 

it not work way expect to.

instead do

while (std::getline(...)) { ... } 

the reason because eof flag isn't set until try read when file @ end. means loop 1 time many, trying read non-existent line add vector.

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there way of separating "words" on space boundary, using std::istringstream , normal input operator >>:

std::istringstream is{a};  std::string word; while (is >> word) {     // `word` }