Maximum of N numbers

Question about the task

Under discussion

Negative numbers - what should happen? I make a break from the loop, but should it ignore ? Maybe something else is wrong?

import java.util.Scanner;

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        int maximum = -2147483648;
        int inputNumber = sc.nextInt();

        while (inputNumber > 0) {
            int inputMaximum = sc.nextInt();
            maximum = Math.max(maximum, inputMaximum);
            inputNumber--;
        }

        if (maximum <= 0) {
        }

        else {
            System.out.println(maximum);
        }
    }
}

Write a program that:
1. reads a number N (must be greater than 0) from the console
2. reads N numbers from the console
3. Displays the maximum of the N entered numbers.

Requirements:

The program should read the numbers from the keyboard.
The program must display a number on the screen.
The class must have a public static void main method.
Don't add new methods to the Solution class.
The program should display the maximum of the N entered numbers.
The program should not display anything if N is less than or equal to 0.

package com.codegym.task.task05.task0532; /* Task about algorithms */ import java.util.Scanner; public class Solution { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(System.in); int maximum = 0; int inputNumber = sc.nextInt(); while (inputNumber > 0) { int inputMaximum = sc.nextInt(); if (inputMaximum <= 0 || inputNumber <= 0) { break; } else { maximum = Math.max(maximum, inputMaximum); } inputNumber--; } if (maximum == 0) { } else { System.out.println(maximum); } } }

Comments (7)

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Cristian

Level 13 , Ploiesti, Romania

12 November 2020, 04:24

public class Solution { public static void main(String[] args) throws Exception { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); int maximum; int N; N = Integer.parseInt(reader.readLine()); if (N > 0) { int array[] = new int[N]; for (int i = 0; i < N; i++) { array[i] = Integer.parseInt(reader.readLine()); } maximum = array[0]; for (int i = 0; i < N; i++) { if (maximum < array[i]) maximum = array[i]; } System.out.println(maximum); } } }

Nouser

Level 36 , Germany

11 November 2020, 13:03

inputNumber must not be <0 but inputMaximum can be smaller (that's why [and cause of line 17] you can delete lines 20 -22). The remaining problem is now, that the maximum is wrong if you input just negative numbers for inputMaximum (line 14)

Anitamalina

Level 18 , København, Denmark

11 November 2020, 19:45

now I just edited my code to above, but I still get the same error. I guess, I don't quite understand the negative numbers then. If I type in 3, followed by fx. -3, -5 and -6 by program doesn't print anything.. shouldn't that be right ?

Nouser

Level 36 , Germany

11 November 2020, 20:10

line 14, you set maximum to 0 line 25, you compare maximum (0) with the input. If it is -1, then the max is still 0, even if that number did not exist so far in your input. Solution... set maximum to the smallest number an int can be (Integer.MIN_VALUE) or initialize it with the first input (needs a little bit of rewriting) Spoiler:

Scanner sc = new Scanner(System.in);

int maximum = Integer.MIN_VALUE;
int inputNumber = sc.nextInt();

if (inputNumber > 0) {
    while (inputNumber > 0) {
        int inputMaximum = sc.nextInt();
        maximum = Math.max(maximum, inputMaximum);
        inputNumber--;
    }
    System.out.println(maximum);
}

Anitamalina

Level 18 , København, Denmark

11 November 2020, 20:25

nice! why do I need an if-statement, before my while loop? to me it's the same, just a prettier code of course ?

Nouser

Level 36 , Germany

12 November 2020, 07:43

Exactly, just a different position of the > 0 check to have it more compact and easier to understand. Above Cristian has posted a solution with my other suggestion, to initialize maximum with the first input. However you do not necessarily need an array for that.

Anitamalina

Level 18 , København, Denmark

12 November 2020, 08:41

Thank you! :D