What is the Preparation Time

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Preparation Time

This exercise focuses on reading a single integer input and using a fixed constant with the multiplication operator to calculate a total amount.

Problem Statement:

Assume each layer of the lasagna takes 2 minutes to prepare. Given the number of layers, $N$, calculate and output the total number of minutes required for preparation.

Example:

Input (N – Layers)	Calculation	Output (Minutes)
2	2 × 2	4

Java Solution and Breakdown

The solution uses the Scanner to read the number of layers (N) and multiplies this input by the constant value of 2 to get the total preparation time.

1. Complete Java Code

import java.util.Scanner;

public class PreparationTime {
    // Define the time per layer as a constant
    public static final int MINUTES_PER_LAYER = 2; 
    
    public static void main(String[] args) {
        // 1. Initialize the Scanner object for input.
        Scanner sc = new Scanner(System.in);

        // 2. Read the number of layers, N.
        int numberOfLayers = sc.nextInt();
        
        sc.close();

        // 3. Calculate the total preparation time: Layers * Minutes Per Layer.
        int totalPreparationTime = numberOfLayers * MINUTES_PER_LAYER;

        // 4. Print the result.
        System.out.println(totalPreparationTime);
    }
}

2. Explanation of Key Concepts

Concept	Code Section	Description
Constant	`public static final int MINUTES_PER_LAYER = 2;`	Defining the fixed rate (2 minutes) as a constant makes the code easy to read and maintain.
Input Reading	`int numberOfLayers = sc.nextInt();`	The `sc.nextInt()` method reads the single integer provided as input.
Multiplication Operator	`numberOfLayers * MINUTES_PER_LAYER`	The core operation uses the multiplication operator (`*`) to scale the number of layers by the constant time rate.
Output	`System.out.println(totalPreparationTime);`	Prints the final integer result to the console on a new line.