StringStream in C++ HackerRank solution

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 ch 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 n integers separated by commas.

Constraints

The length of str is less than 8×10⁵.

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) {
	stringstream ss(str);
    vector<int> result;
    char ch;
    int tmp;

    while (ss >> tmp) 
    {
        result.push_back(tmp);
        ss >> ch;
    }

    return result;
}
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;
}