Sample task and solution : Stringstream in c++ of HackerRank

 In this challenge, we work with string streams.

stringstream is a stream class to operate on strings. It implements input/output operations on memory (string) based streams. stringstream can be helpful in different type of parsing. The following operators/functions are commonly used here

• Operator >> Extracts formatted data.
• Operator << Inserts formatted data.
• Method str() Gets the contents of underlying string device object.
• Method str(string) Sets the contents of underlying string device object.

Its header file is sstream.

One common use of this class is to parse comma-separated integers from a string (e.g., "23,4,56").

stringstream ss("23,4,56");
char ch;
int a, b, c;
ss >> a >> ch >> b >> ch >> c;  // a = 23, b = 4, c = 56

Here  is a storage area for the discarded commas.

If the >> operator returns a value, that is a true value for a conditional. Failure to return a value is false.

Given a string of comma delimited integers, return a vector of integers.

Function Description

Complete the parseInts function in the editor below.

parseInts has the following parameters:

• string str: a string of comma separated integers

Returns

• vector<int>: a vector of the parsed integers.

Note You can learn to push elements onto a vector by solving the first problem in the STL chapter.

Input Format

There is one line of  integers separated by commas.

Constraints

The length of  is less than .

Sample Input

23,4,56

Sample Output

23
4
56

Solution

#include <sstream>

#include <vector>

#include <iostream>

using namespace std;

vector<int> parseInts(string str) {

    // Complete this function

    // Complete this function

    stringstream ss(str);

    char ch;

    int i, a;

    vector<int> list;

    while(ss){

        ss >> a >> ch;

        list.push_back(a);

       

    }

    return list;

}

int main() {

    string str;

    cin >> str;

    vector<int> integers = parseInts(str);

    for(int i = 0; i < integers.size(); i++) {

        cout << integers[i] << "\n";

    }

   

    return 0;

}

Source : HackerRank