Hackerrrank : Input and Output (C++)

SOLUTION C++ : 

#include <cmath>

#include <cstdio>

#include <vector>

#include <iostream>

#include <algorithm>

using namespace std;

int main() {

    /* Enter intyour code here. Read input from STDIN. Print output to STDOUT */   

    int a,b,c,d ;

    cin>>a ; cin>>b ; cin>> c ;

    d = a +b + c + d ;

    cout<<d ; 

    return 0 ;

}

Objective
In this challenge, we're practicing reading input from stdin and printing output to stdout.

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In C++, you can read a single whitespace-separated token of input using cin, and print output to stdout using cout. For example, let's say we declare the following variables:

string s;
int n;

and we want to use cin to read the input "High 5" from stdin. We can do this with the following code:

cin >> s >> n;

The above code reads the first word ("High") from stdin and saves it as string , then reads the second word ("") from stdin and saves it as integer . If we want to print these values to stdout, we write the following code:

cout << s << " " << n << endl;

The above code prints the contents of string , which is the word "High". Then it prints a single space (), followed by the contents of integer . Because we also want to ensure that nothing else is printed on this line, we end our line of output with a newline via endl. This results in the following output:

High 5

Task
Read  numbers from stdin and print their sum to stdout.

Note: If you plan on completing this challenge in C instead of C++, you'll need to use format specifiers with printf and scanf.

Input Format

A single line containing  space-separated integers: , , and .

Constraints

Output Format

Print the sum of the three numbers on a single line.

Sample Input

1 2 7

Sample Output

10

Explanation

The sum of the three numbers is .