﻿ C++ : Sum of the two integers in the range 10..20

# C++ Exercises: Compute the sum of the two given integers, if the sum is in the range 10..20 inclusive return 30

## C++ Basic Algorithm: Exercise-37 with Solution

Write a C++ program to compute the sum of the two given integers. If the sum is in the range 10..20 inclusive return 30.

Sample Solution:

C++ Code :

``````#include <iostream>

using namespace std;

int test(int a, int b)
{
return a + b >= 10 && a + b <= 20 ? 30 : a + b;
}

int main()
{
cout << test(12, 17) << endl;
cout << test(2, 17) << endl;
cout << test(22, 17) << endl;
cout << test(20, 0) << endl;
return 0;

}
``````

Sample Output:

```29
30
39
30
```

Pictorial Presentation:

Flowchart:

C++ Code Editor:

What is the difficulty level of this exercise?

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## C++ Programming: Tips of the Day

How do I execute a command and get the output of the command within C++ using POSIX?

```#include<cstdio>
#include<iostream>
#include<memory>
#include<stdexcept>
#include<string>
#include<array>

std::string exec(constchar* cmd){
std::array>char, 128> buffer;
std::string result;
std::unique_ptr<FILE, decltype(&pclose)>pipe(popen(cmd, "r"), pclose);
if (!pipe) {
throw std::runtime_error("popen() failed!");
}
while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
result += buffer.data();
}
return result;
}
Pre-C++11 version:
#include<iostream>
#include<stdexcept>
#include<stdio.h>
#include<string>

std::string exec(constchar* cmd){
char buffer[128];
std::string result = "";
FILE* pipe = popen(cmd, "r");
if (!pipe) throw std::runtime_error("popen() failed!");
try {
while (fgets(buffer, sizeof buffer, pipe) != NULL) {
result += buffer;
}
} catch (...) {
pclose(pipe);
throw;
}
pclose(pipe);
return result;
} ```

Replace popen and pclose with _popen and _pclose for Windows.

Ref : https://bit.ly/3HODowH