Find Maximum and Minimum of N Integers | MinMax Program for Java

[Hiche]

Homework Statement

Write a program that reads a number N from the command line and asks the user to enter N integers. The program should compute their minimum and maximum, and prints them out.

Homework Equations

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The Attempt at a Solution

public class MinMax 
{
	public static void main(String[] args)
	{
		int N = Integer.parseInt(args[0]);
		int userInput = 0;
		int maximum = 0;
		int minimum = ?;
		
		for (int i = 1; i <= N; i++)
		{
			StdOut.print("Enter integer " + i + ": ");
			userInput = StdIn.readInt();
			if (userInput > maximum)
				maximum = Math.max(maximum, userInput);
			if (userInput < minimum)
				minimum = Math.min(minimum, userInput);
		}
		StdOut.println(maximum + " " + minimum);
		
		
	}
}

The question mark is where I need help. If I input a large number, it works. But is it the only way? We are limited to using the standard input command StdIn. This is an easy question I know, but I was just looking for an alternative.

 

[MisterX]

I don't think you should initialize either minimum or maximum to constants.

There is a problem with

int maximum = 0;

if all the numbers entered by the user are negative.

Instead, the first iteration could have different behavior than the others. On the first interation, minimum and maximum are both set to the first element.

 

[Hiche]

                for (int i = 1; i <= N; i++)
		{
			System.out.print("Enter integer " + i + ": ");
			userInput = StdIn.readInt();
			if (i == 1)
			{
				maximum = userInput;
				minimum = userInput;
			}
			if (userInput > maximum)
				maximum = Math.max(maximum, userInput);
			if (userInput < minimum)
				minimum = Math.min(minimum, userInput);
		}

Something like this? I'm guessing there is a better way.

 

[MisterX]

Yes, that should be okay, although it might be better to put "continue;" at the end of that first if block, since there is no need for comparisons on the first iteration.

 

[DeeNos]

One alternative could be to initialize the minimum variable to the first user input, assuming that the user will always input at least one integer. This way, the minimum will be updated as the user inputs more integers, and the if statement for checking the minimum can be removed. Another alternative could be to use Integer.MAX_VALUE for the initial value of minimum, as it is the largest possible integer value and will be updated as the user inputs smaller integers.