Vfrdtyky

So there are Q lines.
Each line has an arbitrary number of integers separated by spaces, I need to process those numbers.

Example Input

Q = 4

12 32 4 3 2

1 2 3 4 

0

2 3 1 223 4 2 3

I am reading each line as string and extracting the numbers as string and then using atoi to convert them to int, ie,

while(Q>0){

        for(char c:s){

            if (c==' '){

                int x = atoi(temp.c_str());

                temp = "";

                //process x

                continue;

            }

            temp +=c;

        }

        Q--;

    }

Surely there is a better way to do this?

Edit: The numbers of each line are processed differently.

For example, say

Line 1 has 1,2,3,4. Line 2 has 14,15.

Then 1,2,3,4 will be processed differently and 13,14 differently.

This is why I can't use std::cin as it ignores all whitespaces (both spaces and newline).

#include <iostream>



// ...



int x;

while (std::cin >> x)

    ; // process x

edited cause of your comment:

#include <iostream>



// ...



int x;

char ch;

while (std::cin >> x >> std::noskipws >> ch >> std::skipws) {

    if (ch == 'n')

        ; // process x differently

}

If you need line oriented parsing and still want to use the power of iostream then I suggest you use std::getline and std::istringstream. Example below

#include <iostream>

#include <sstream>



int main() {

    char ch = '';

    std::cin >> ch;

    if (!std::cin || ch != 'Q') return EXIT_FAILURE;

    std::cin >> ch;

    if (!std::cin || ch != '=') return EXIT_FAILURE;

    int Q = 0;

    std::cin >> Q;

    if (!std::cin) return EXIT_FAILURE;

    std::string line;

    std::getline(std::cin, line); // get ready for a new line

    while (Q > 0) {

        if (!std::getline(std::cin, line)) return EXIT_FAILURE;

        std::istringstream iss(line);

        int count = 0;

        int sum = 0;

        int i;

        while (iss >> i) {

            ++count;

            sum += i;

        }

        std::cout << "Found " << count << " integers who's sum was " << sum << 'n';

        Q--;

    }

    std::cout << "Donen";

}