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Centimeters to Millimeters Conversion

Concept Explanation

What is it?

This program converts a length value given in centimeters (cm) to its equivalent in millimeters (mm). Millimeters and centimeters are units of length in the metric system, with 1 centimeter being equal to 10 millimeters. This conversion is the reverse of millimeters to centimeters.

Why is it important?

Unit conversion is a fundamental skill in various fields, ensuring consistency and comparability of measurements. In programming, it provides a straightforward example of applying a conversion factor, handling numerical inputs, and presenting results.

Where is it used?

• Engineering and Design: Converting between common metric units for precision work or larger scale plans.
• Crafts and Hobbies: Adjusting patterns or instructions that might be in different metric subunits.
• Science Education: Illustrating basic metric conversions.

Real-world example

If you are designing a small component and its dimensions are given in centimeters (e.g., a screw with a length of 2.5 cm), but you need to work with a tool that requires measurements in millimeters, you would convert it. 2.5 cm converts to 25 mm.

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Algorithm

1. Start.
2. Get the length in centimeters (centimeters) from the user.
3. Apply the conversion formula: millimeters = centimeters * 10.
4. Display the original length in centimeters and the calculated length in millimeters.
5. End.

Conversion Formula: Millimeters = Centimeters × 10

Edge Cases: - Non-numeric input for length (handled by language-specific error mechanisms or explicit validation). - Zero or negative lengths: A length cannot be zero or negative. The program should ideally handle these inputs by requesting valid dimensions.

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Implementations

Java (JDK 17)Python (3.10+)C (C99)Oracle (19c)

import java.util.Scanner;

public class CmToMm {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter length in centimeters (cm): ");
        double centimeters = scanner.nextDouble();

        // Convert centimeters to millimeters
        double millimeters = centimeters * 10;

        System.out.println("Centimeters: " + centimeters + " cm");
        System.out.println("Millimeters: " + String.format("%.2f", millimeters) + " mm");

        scanner.close();
    }
}

# Get length in centimeters from user
centimeters_str = input("Enter length in centimeters (cm): ")
centimeters = float(centimeters_str)

# Convert centimeters to millimeters
millimeters = centimeters * 10

print(f"Centimeters: {centimeters} cm")
print(f"Millimeters: {millimeters:.2f} mm") # Format to 2 decimal places

#include <stdio.h>

int main() {
    double centimeters, millimeters;

    printf("Enter length in centimeters (cm): ");
    scanf("%lf", &centimeters);

    // Convert centimeters to millimeters
    millimeters = centimeters * 10;

    printf("%.2lf cm is equal to %.2lf mm\n", centimeters, millimeters);

    return 0;
}

SET SERVEROUTPUT ON;
DECLARE
  cm_val  NUMBER := &Enter_Length_in_cm;
  mm_val  NUMBER;
BEGIN
  DBMS_OUTPUT.PUT_LINE('--- Centimeters to Millimeters Conversion ---');
  DBMS_OUTPUT.PUT_LINE('Centimeters: ' || cm_val || ' cm');

  mm_val := cm_val * 10;

  DBMS_OUTPUT.PUT_LINE('Millimeters: ' || ROUND(mm_val, 2) || ' mm');
END;
/

Explanation

• Java: Uses double for length values. Scanner reads the centimeter input, and the multiplication is performed directly. String.format("%.2f", ...) formats the output.
• Python: Reads input as a string and converts to float. Applies the multiplication and uses an f-string to display formatted output.
• C: Reads double input using scanf("%lf", ...) for centimeters. The multiplication is performed, and printf("%.2lf\n", ...) displays the formatted result.
• Oracle: Implemented in PL/SQL. Uses NUMBER data type for length. Substitution variable (&Enter_Length_in_cm) for input. ROUND() is used for formatting the millimeter output.

Complexity Analysis

• Time Complexity: O(1) - The number of arithmetic operations is constant.
• Space Complexity: O(1) - A fixed number of variables are used.

Flowchart

graph TD
    A[Start] --> B[Get Centimeters]
    B --> C[Calculate Millimeters = Centimeters * 10]
    C --> D[Display Centimeters and Millimeters]
    D --> E[End]

Sample Dry Run

Step	Centimeters	Millimeters	Description
Input	10.0	-	User enters 10.0
Process	10.0	100.0	Millimeters = 10.0 * 10 = 100.0
Output	10.0	100.0	Display "10.00 cm is 100.00 mm"
End	-	-	Program terminates

Practice Problems

Easy

• Modify the program to convert meters to kilometers.
• Convert feet to inches.

Medium

• Implement input validation to ensure positive numbers are entered for length.
• Create a program that converts between different units of volume (e.g., liters to milliliters).

Hard

• Develop a unit conversion utility that can handle multiple unit types (length, mass, volume, temperature) based on user choice, with a focus on bidirectional conversion.

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