Question

write a program in C++ to read an array of stored integers. Search for a value using binary search method. If the element is found, print its location else print element not found

Answer 1

#include <malloc.h>
#include <iostream>

using namespace std;

void bubbleSort(int* arr, int size);
int searchBinary(int *arr, int left, int right, int key);

int main() {
int *array; // a pointer to an array
int i, size;
int key = 0;

cout << ("Enter the size of the array: ");
cin >> size;
// Allocating memory
array = (int*)malloc(size * sizeof(int));
// Enter the array elements
for (i = 0; i < size; i++)
{
cout << "[" << i << "] = ";
cin >> array[i];
}

bubbleSort(array, size);

// Conclusion sorted array elements
cout << "Sorted array:" << endl;
for (i = 0; i < size; i++)
cout << "[" << i << "] = " << array[i] << endl;

cout << "\nEnter the key: ";
cin >> key;

int errorCode = 0;
errorCode = searchBinary(array, 0, size, key);
if (errorCode != -1)
{
cout << "The index of the element found: " << errorCode << endl;
}
else cout << "Element not found!" << endl;

free(array);

system("pause");

return 0;
}

void bubbleSort(int* arr, int size)
{
int tmp, i, j;

for (i = 0; i < size - 1; ++i) // i - passage number
{
for (j = 0; j < size - 1; ++j) // the inner passage cycle
{
if (arr[j + 1] < arr[j])
{
tmp = arr[j + 1];
arr[j + 1] = arr[j];
arr[j] = tmp;
}
}
}
}

// a binary search algorithm function
int searchBinary(int *arr, int left, int right, int key)
{
int midd = 0;
while (1)
{
midd = (left + right) / 2;

if (key < arr[midd]) // if less than the required value in the cell
right = midd - 1; // displace the right search border
else if (key > arr[midd]) // if desired more than the value in the cell
left = midd + 1; // search displace left border
else // otherwise (values are equal)
return midd; // the function returns the index of the cell

if (left > right) // if border closed
return -1;
}
}