How to take delimiter as -0 between array size and array value of integer in c++

Question

How to take delimiter as -0 between array size and array value of integer in c++.

for example: 2 -0 1,2 -0
array-size '-0' 1st array values separated by "," '-0'

If I take input in a string using get line then how to separate size from the string and take input of array.

int main(){

string s,t;

getline(cin,s);

stringstream x(s);

while(getline(x,t,"-0")){
    cout << t;
}

}

I cannot understand delimiter concept properly from google, can you explain it and take input in the: " array-size '-0' 1st array values separated by ',' '-0' " form.

I'm having the greatest difficulty understanding what you want to achieve. Can you give some context? What's an array size of -0? — JHBonarius, Oct 17 '20 at 19:04
Does this answer your question? [Parse (split) a string in C++ using string delimiter (standard C++)](https://stackoverflow.com/questions/14265581/parse-split-a-string-in-c-using-string-delimiter-standard-c) — moooeeeep, Oct 18 '20 at 12:37

Eljay · Accepted Answer · 2020-10-18T12:29:29.450

Given the input, the easiest way is to check the string token as being the -0 delimiter.

#include <iostream>
#include <sstream>
#include <string>

using std::cin;
using std::cout;
using std::getline;
using std::string;
using std::stringstream;

int main(){
    string s,t;
    getline(cin, s);
    stringstream x(s);
    char const* sep = "";
    while (x >> t) {
        if (t == "-0") {
            cout << sep << "<DELIMITER>";
        } else {
            cout << sep << t;
        }
        sep = " ";
    }
    cout << "\n";
}

That gives:

echo '2 -0 1,2 -0' | ./a.out
2 <DELIMITER> 1,2 <DELIMITER>

Update

Storing the values into a std::vector<int>.

#include <cstddef>
#include <iostream>
#include <sstream>
#include <stdexcept>
#include <string>
#include <vector>

using std::cin;
using std::cout;
using std::getline;
using std::ostream;
using std::runtime_error;
using std::size_t;
using std::stoi;
using std::string;
using std::stringstream;
using std::vector;

static auto MakeVecInt(string line) -> vector<int> {
    auto result = vector<int>();
    auto ss = stringstream(line);
    auto value = string{};

    while(getline(ss, value, ',')) {
        result.push_back(stoi(value));
    }

    return result;
}

static auto operator<<(ostream& out, vector<int> const& v) -> ostream& {
    char const* sep = "";

    for (auto i : v) {
        out << sep << i;
        sep = " ";
    }

    return out;
}

int main() {
    auto line = string{};
    getline(cin, line);
    auto ss = stringstream(line);

    auto count = size_t{};
    auto delimiter1 = string{};
    auto values = string{};
    auto delimiter2 = string{};

    if (!(ss >> count >> delimiter1 >> values >> delimiter2))
        throw runtime_error("bad input");

    if (delimiter1 != "-0" || delimiter2 != "-0")
        throw runtime_error("bad input");

    auto vec = MakeVecInt(values);

    if (count != vec.size())
        throw runtime_error("bad input");

    cout << vec << "\n";
}

Update

Note in the above code the vector<int> output routine:

static auto operator<<(ostream& out, vector<int> const& v) -> ostream&

It outputs each element in the vector, with a space between each element. It does not output a space before the first element.

Please don't make your life harder than it needs to be. Those using declarations and that function declaration syntax just needlessly complicates the provided example. Or is this effect intended? — moooeeeep, Oct 18 '20 at 12:47
@moooeeeep • It is intentional. I prefer to post complete examples, not snippets that presume C++ novices will be able to fill in the blanks themselves. — Eljay, Oct 18 '20 at 12:50

How to take delimiter as -0 between array size and array value of integer in c++

1 Answers1