split string into character and integer c++

Question

I am working on a small assignment, and part of it requires me to split the string into integers and characters. These integers and characters are then stored in separate vectors. For example, if I enter '* + / 9 8 7', I want to store the '*','+' and '/' in one vector and the 9, 8, and 7 in another vector. Below is the code I wrote for this program

string InputString;
getline(cin,InputString);
stringstream ss(InputString);
vector<int>operands;
vector<char>operators;
char op;
int num;
while(ss>>op)
{

    if((op=='+')||(op=='-')||(op=='*')||(op=='/'))
    {
        operators.push_back(op);
    }
    else
    {
        ss>>num;    
        operands.push_back(num);
    }
}

for (unsigned int k = 0;k<operands.size();k++)
{
    cout<<operands[k]<<" ";
}

cout<<endl;

for (unsigned int x = 0;x<operators.size();x++)
{
    cout<<operators[x]<<" ";
}

The problem is that my output does not store the integers correctly. My characters are stored correctly (when I print out the contents of my integer vector in my second for loop, I only get the last number entered). I hope that my question is not too confusing. I couldn't find other related posts on StackOverflow

Have you tried to use a debugger? It's easy to find the error with it. — Danh, Oct 29 '16 at 03:25
`while(ss>>op)` ate the first character of the number. You'll have to put it back. — user4581301, Oct 29 '16 at 06:04

score 0 · Accepted Answer · answered Oct 29 '16 at 13:33

0

To recover all digits of the number, you have to unget() the tested character.

Add the ss.unget(); just before parsing the number as follow:

else
{
    ss.unget(); // recover the op character
    ss>>num;
    operands.push_back(num);
}

answered Oct 29 '16 at 13:33

J. Piquard

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split string into character and integer c++

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