#include <iostream>
#include <cstring>
#include <unistd.h>
#include <sys/utsname.h>

int main() {
    char newHostname[] = "newhostname"; // Replace with the desired hostname

    if (sethostname(newHostname, strlen(newHostname)) == 0) {
        std::cout << "Hostname set to: " << newHostname << std::endl;

        // Optionally, update the /etc/hostname file to make the change permanent
        FILE *hostnameFile = fopen("/etc/hostname", "w");
        if (hostnameFile != NULL) {
            fprintf(hostnameFile, "%s\n", newHostname);
            fclose(hostnameFile);
        } else {
            perror("Failed to update /etc/hostname");
        }
    } else {
        perror("Failed to set hostname");
    }

    return 0;
}

#include <iostream>
using namespace std;

int main()
{
    cout << "Hello, World!" << endl;
    return 0;
}

using namespace std; 
  
class Hash 
{ 
    int BUCKET;    // No. of buckets 
  
    // Pointer to an array containing buckets 
    list<int> *table; 
public: 
    Hash(int V);  // Constructor 
  
    // inserts a key into hash table 
    void insertItem(int x); 
  
    // deletes a key from hash table 
    void deleteItem(int key); 
  
    // hash function to map values to key 
    int hashFunction(int x) { 
        return (x % BUCKET); 
    } 
  
    void displayHash(); 
}; 
  
Hash::Hash(int b) 
{ 
    this->BUCKET = b; 
    table = new list<int>[BUCKET]; 
} 
  
void Hash::insertItem(int key) 
{ 
    int index = hashFunction(key); 
    table[index].push_back(key);  
} 
  
void Hash::deleteItem(int key) 
{ 
  // get the hash index of key 
  int index = hashFunction(key); 
  
  // find the key in (inex)th list 
  list <int> :: iterator i; 
  for (i = table[index].begin(); 
           i != table[index].end(); i++) { 
    if (*i == key) 
      break; 
  } 
  
  // if key is found in hash table, remove it 
  if (i != table[index].end()) 
    table[index].erase(i); 
} 
  
// function to display hash table 
void Hash::displayHash() { 
  for (int i = 0; i < BUCKET; i++) { 
    cout << i; 
    for (auto x : table[i]) 
      cout << " --> " << x; 
    cout << endl; 
  } 
} 
  
// Driver program  
int main() 
{ 
  // array that contains keys to be mapped 
  int a[] = {15, 11, 27, 8, 12}; 
  int n = sizeof(a)/sizeof(a[0]); 
  
  // insert the keys into the hash table 
  Hash h(7);   // 7 is count of buckets in 
               // hash table 
  for (int i = 0; i < n; i++)  
    h.insertItem(a[i]);   
  
  // delete 12 from hash table 
  h.deleteItem(12); 
  
  // display the Hash table 
  h.displayHash(); 
  
  return 0; 
}

/*
Good morning! Here's your coding interview problem for today.

This problem was asked by Stripe.

Given an array of integers, find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can contain duplicates and negative numbers as well.

For example, the input [3, 4, -1, 1] should give 2. The input [1, 2, 0] should give 3.

You can modify the input array in-place.
*/
#include <iostream>
using namespace std;

int calcMissing(int* input, int size)
{
	int sum = 0;
	int n = 1; //add one to account for missing value
	for(int i = 0; i < size; i++)
	{
	if(input[i] > 0)
	{
	sum += input[i];
	n++;
	}
	}

	//If no numbers higher than 0, answer is 1
	if(sum == 0)
	return 1;

	return (n*(n+1)/2) - sum; //Formula is expectedSum - actualSum
	/* expectedSum = n*(n+1)/2, the formula for sum(1, n) */
}

int main()
{

	cout << calcMissing(new int[4]{3, 4, -1, 1}, 4) << endl;
	cout << calcMissing(new int[3]{1, 2, 0}, 3) << endl;

	//No positive numbers
	cout << calcMissing(new int[1]{0}, 1) << endl;
}

#include <iostream>
using namespace std;

int main() {

cout << "Hello World!\n";
// Prints out "Hello World"
return 0;

}

#include <iostream>
using namespace std;

int main() {
  const int ROW_SIZE = 2;
  const int COLUMN_SIZE = 5;              //establish all variables
  int matrix[ROW_SIZE][COLUMN_SIZE];
  int minVal;

  for (int i = 0; i < ROW_SIZE; ++i)    // for loop to ask user to enter data.
  {
    for (int h = 0; h < COLUMN_SIZE; ++h) {
      cout << "Enter data for row #" << i + 1 << " and column #" << h + 1 << ": ";
      cin >> matrix[i][h];
    }
  }
  cout << "You entered: " << endl;
  for (int i = 0; i < ROW_SIZE; ++i) //for statements to output the array neatly
  {
    for (int h = 0; h < COLUMN_SIZE; ++h) {
      cout << matrix[i][h] << "\t";
    }
    cout << endl;
  }

  cout << "Minimum for each row is: {";
  for (int i = 0; i < ROW_SIZE; i++) //for statements to find the minimum in each row
  {
    minVal = matrix[i][0];

    for (int h = 0; h < COLUMN_SIZE; h++) {
      if (matrix[i][h] < minVal) // if matrix[i][h] < minVal -> minVal = matrix[i][h];
      {
        minVal = matrix[i][h];
      }
    }
    cout << minVal << ", ";
  }
  cout << "}" << endl;

  cout << "Minimum for each column is: {";
  for (int i = 0; i < COLUMN_SIZE; i++) //for statements to find the minimum in each column
  {
    minVal = matrix[0][i];
    for (int h = 0; h < ROW_SIZE; h++) {
      if (matrix[h][i] < minVal) //replaces minVal with array index for that column that is lowest
      {
        minVal = matrix[h][i];
      }
    }
    cout << minVal << ", ";
  }
  cout << "}" << endl;

  return 0;
}