﻿ C++ : Check every 5 appears in an array is next to another 5

# C++ Exercises: Check a given array of integers and return true if every 5 that appears in the given array is next to another 5

## C++ Basic Algorithm: Exercise-113 with Solution

Write a C++ program to check a given array of integers and return true if every 5 that appears in the given array is next to another 5.

Sample Solution:

C++ Code :

``````#include <iostream>
using namespace std;

static bool test(int numbers[], int arr_length)
{
bool flag = true;

for (int i = 0; i < arr_length; i++)
{
if (numbers[i] == 5)
{
if ((i > 0 && numbers[i - 1] == 5) || (i < arr_length - 1 && numbers[i + 1] == 5)) flag = true;
else if (i == arr_length - 1) flag = false;
else return false;
}
}
return flag;
}

int main()
{
int nums1[] = {3, 5, 5, 3, 7};
int arr_length = sizeof(nums1) / sizeof(nums1[0]);
cout << test(nums1, arr_length) << endl;
int nums2[] = {3, 5, 5, 4, 1, 5, 7};
arr_length = sizeof(nums2) / sizeof(nums2[0]);
cout << test(nums2, arr_length) << endl;
int nums3[] = {3, 5, 5, 5, 5, 5};
arr_length = sizeof(nums3) / sizeof(nums3[0]);
cout << test(nums3, arr_length) << endl;
int nums4[] = {2, 4, 5, 5, 6, 7, 5};
arr_length = sizeof(nums4) / sizeof(nums4[0]);
cout << test(nums4, arr_length) << endl;
return 0;
}
``````

Sample Output:

```1
0
1
0
```

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