镜头焦距程序

编写程序以确定镜头的焦距。
焦距是镜片中心到主要焦点之间的距离。为了确定透镜的焦距，我们应该知道透镜与图像之间的距离(I)以及透镜与物体之间的距离(O)。在这里，我们将使用镜头方程式，也称为焦距方程式。
透镜方程为：

$\frac{1} {F}$ = $\frac {1}{O}$ + $\frac{1}{I}$

这里，
F是焦距
我是镜头和图像之间的距离
O是镜头与物体之间的距离
例子 ：

Input : O = 50, I = 2
Output : F = 1.92308

Input : O = 25, I = 5
Output : F = 4.16667

C++

// C++ program to determine
// the focal length of a lens
#include 
using namespace std;
 
// Function to determine the focal length of a lens
float focal_length(float image_distance, float object_distance)
{
    return 1 / ((1 / image_distance) + (1 / object_distance));
}
 
// Driver function
int main()
{
    // variable to store the distance
    // between the lens and the image
    float image_distance = 2;
 
    // variable to store the distance
    // between the lens and the object
    float object_distance = 50;
 
    cout << "Focal length of a lens is "
         << focal_length(image_distance, object_distance)
         << " units .";
 
    return 0;
}

Java

// Java program to determine
// the focal length of a lens
 
import java.io.*;
 
class GFG {
 
    // Function to determine the focal
    // length of a lens
    static float focal_length(float image_distance,
                              float object_distance)
    {
        return 1 / ((1 / image_distance) +
                           (1 / object_distance));
    }
 
    public static void main(String[] args)
    {
 
        // variable to store the distance
        // between the lens and the image
        float image_distance = 2;
 
        // variable to store the distance
        // between the lens and the object
        float object_distance = 50;
         
        System.out.println("Focal length of a lens is "
        + focal_length(image_distance, object_distance)
                                         + " units.");
    }
}
 
// This code is contributed by Ajit.

Python3

# Python3 program to determine
# the focal length of a lens
 
# Function to determine the focal length of a lens
def focal_length(image_distance, object_distance)
    : return 1 / ((1 / image_distance) + (1 / object_distance))
 
# Driver Code
# Variable to store the distance
# between the lens and the image
image_distance = 2
 
# Variable to store the distance
# between the lens and the object
object_distance = 50
 
result = focal_length(image_distance, object_distance)
print("Focal length of a lens is ", result, " units.")

C#

// C# program to determine
// the focal length of a lens
using System;
 
class GFG {
 
    // Function to determine the focal
    // length of a lens
    static float focal_length(float image_distance,
                            float object_distance)
    {
        return 1 / ((1 / image_distance) +
                    (1 / object_distance));
    }
     
    // Driver code
    public static void Main()
    {
 
        // variable to store the distance
        // between the lens and the image
        float image_distance = 2;
 
        // variable to store the distance
        // between the lens and the object
        float object_distance = 50;
         
        Console.WriteLine("Focal length of a lens is "
        + focal_length(image_distance, object_distance)
                                        + " units.");
    }
}
 
// This code is contributed by Vt_m.

Javascript

 
// javascript program to determine
// the focal length of a lens
 
// Function to determine the focal
    // length of a lens
    function focal_length(image_distance,
                              object_distance)
    {
        return 1 / ((1 / image_distance) +
                           (1 / object_distance));
    }
   
 
// Driver Function
 
         // variable to store the distance
        // between the lens and the image
        let image_distance = 2;
   
        // variable to store the distance
        // between the lens and the object
        let object_distance = 50;
           
        document.write("Focal length of a lens is "
        + focal_length(image_distance, object_distance)
                                         + " units.");
            

输出 ：

Focal length of a lens is 1.92308 units .