midpoint() in C++20 with Examples

The function midpoint() computes the midpoint of the integers, floating-points, or pointers a and b.
Header File:

<numeric>

Parameters: This function accepts two data types like integers, floating points, pointer values.

Return:

It returns the midpoints of the given data types.
Algorithm this function implements:

• Half the sum of a and b without any overflow. Same as, (a + b)/2.
• If a and b are integer types and the sum is odd, the result is rounded towards a.
• If a and b are floating-point types, at most one inexact operation occurs (rounded towards zero).
• If a and b are pointing to x[i] and x[j] respectively of the same array object x (for the purpose of pointer arithmetic), the result will be a pointer to x[i + (j – i)/2] (or, equivalently x[std::midpoint(i, j)]) where the division rounds towards zero. If a and b do not point to elements of the same array object, the behavior is undefined.

Uses Of midpoint() function:

• Middle point of two integers using midpoint(): Below is the C++ Program to demonstrate the middle point of two integer numbers using midpoint():

C++

// C++ program to demonstrate the
// midpoint function
#include <iostream>
#include <numeric>
using namespace std;

// Driver Code
int main()
{
    // a and b both of integer type
    int a = 3;
    int b = 6;

    cout << "midpoint(" << a << ", "
         << b << "): "
         << midpoint(a, b) << endl;

    a = 6;
    b = 3;
    cout << "midpoint(" << a
         << ", " << b << "): "
         << midpoint(a, b) << endl;

    return 0;
}

Output:

• midpoint() can handle cases like an overflow: Below is the C++ program to demonstrate how to handle overflow using midpoint():
  

C++

// C++ program for the above approach
#include <climits>
#include <iostream>
#include <numeric>
using namespace std;

// Driver Code
int main()
{
    // a stores maximum storable
    // value of integer
    int a = INT_MAX;

    // b stores maximum storable
    // value of integer - 2
    int b = INT_MAX - 2;

    cout << "a: " << a << endl
         << "b: " << b << endl
         << "Incorrect (overflow"
         << " and wrapping): "
         << (a + b) / 2 << endl
         << "Correct: "
         << midpoint(a, b) << "\n\n";

    return 0;
}

Output:

• Middle point of two floating number using midpoint(): Below is the C++ program to demonstrate how to find the middle point of two floating-point numbers using midpoint():

C++

// C++ program for the above approach
#include <iostream>
#include <numeric>

using namespace std;

int main()
{
    // x and y both floating type
    float x = 6.56;
    float y = 7.23;

    cout << "midpoint(" << x
         << ", " << y << "): "
         << midpoint(x, y) << endl;

    x = 2.0;
    y = 3.0;

    cout << "midpoint(" << x
         << ", " << y << "): "
         << midpoint(x, y)
         << endl
         << endl;
}

Output:

• Middle point between two pointers pointing to the same object using midpoint(): Below is the C++ program to demonstrate how to find the middle point of two pointers pointing to the same object using midpoint():
  

C++

// C++ program for the above approach
#include <iostream>
#include <numeric>
using namespace std;

// Driver Code
int main()
{
    // str is a character array
    char str[] = "GeeksforGeeks";

    // str1 is pointing to the
    // 5-th element in str
    char* str1 = &str[4];

    // str2 is pointing to the
    // 10-th element in str
    char* str2 = &str[9];

    // str1 and str2 is pointing same
    // object str therefore, we can
    // logically compute and point a
    // middle element in str
    cout << "midpoint('" << *str1
         << "', '" << *str2 << "'): '"
         << *midpoint(str1, str2)
         << "'" << endl;

    cout << "midpoint('" << *str2
         << "', '" << *str1 << "'): '"
         << *midpoint(str2, str1)
         << "'" << endl;
}

Output: