yoland carls

Good points. I will try to make it better.

Hi, I made it...

import java.util.*; public class m { private static int sum = 35; public static void main(String[] args) { Scanner scan = new Scanner(System.in); System.out.println("Enter num of values in array: "); int [] arr = new int[scan.nextInt()]; for(int i=0;i<arr.length; i++) { scan = new Scanner(System.in); System.out.println("please enter a value: "); while(scan.hasNextInt()){ int x = scan.nextInt() ; arr[i]= x; break; } } for(int i:arr){ System.out.print(" " + i ); } Arrays.sort(arr); Map<Integer, Integer> intMap = new Hashtable<Integer, Integer>(); for (int j=0; j<arr.length; j++) { intMap.put(j, arr[j]); if(intMap.containsValue(sum - arr[j])) System.out.println("\n Found pair of numbers : "+arr[j] +" and "+(sum - arr[j])); } System.out.println(intMap); } } Result: Enter num of values in array: 6 please enter a value: 10 please enter a value: 25 please enter a value: 30 please enter a value: 5 please enter a value: 6 please enter a value: 4 10 25 30 5 6 4 Found pair of numbers : 25 and 10 Found pair of numbers : 30 and 5 {5=30, 4=25, 3=10, 2=6, 1=5, 0=4}



Thank you for breaking up the steps!

Hello,

Here is the code to enter ints and with a check for no ints:
import java.util.*; public class Five { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Enter Numbers "); int count = 0; int userInput; try { userInput = input.nextInt(); while (userInput != 0) { userInput = input.nextInt(); } } catch (InputMismatchException iex) { System.out.println("Sorry You have entered a invalid input"); } catch (Exception e) { System.out.println("Something went wrong :-( "); } } }


Thank you!

Yes, it displays:

Enter a Number
9

Sorry, here it is:

import java.util.*; public class Five { public static void main(String[] args) { int userInputArray; Scanner input = new Scanner(System.in); System.out.println("Enter a Number "); int x = input.nextInt(); } }

So, when I add the code to display the pairs that add to 35 as below:
(The name of the array is inArray here)

import java.util.*;

class Four {


private static int[] intArray;
private static int sum = 35;


public static void main(String[] args) {


Scanner input = new Scanner(System.in);
System.out.println("Enter 10 Numbers ");
int count = 0;
int x;
try {
do {
x = input.nextInt();
if (x != 0) {
System.out.println("Given Number is " + x);
int[] intArray = new int[10];
intArray[0] = x;

} else {
System.out.println("Program will stop Getting input from USER");
break;
}
count++;
} while (x != 0 && count < 10);
} catch (InputMismatchException iex) {
System.out.println("Sorry You have entered a invalid input");
} catch (Exception e) {
System.out.println("Something went wrong :-( ");
}
// Code to display pairs that add to 35
Map<Integer, Integer> intMap = new Hashtable<Integer, Integer>();
for (int i=0; i<intArray.length; i++)
{
intMap.put(i, intArray[i]);
System.out.println("i " + i + " array " + +intArray[i]);

if(intMap.containsValue(sum - intArray[i]))
System.out.println("Found numbers : "+intArray[i] +" and "+(sum - intArray[i]));

}
System.out.println(intMap);

}
}

Running the program I get error: Exception in thread "main" java.lang.NullPointerException
at Four.main(Four.java:39)

Hello,

This is the program to enter the numbers with the scanner:

import java.util.*;


public class One {

public static void main(String[] args) {

List<Integer> userInputArray = new ArrayList<Integer>();

Scanner input = new Scanner(System.in);
System.out.println("Enter 10 Numbers ");
int count = 0;
int x;
try {
do {
x = input.nextInt();
if (x != 0) {
System.out.println("Given Number is " + x);
userInputArray.add(x);
} else {
System.out
.println("Program will stop Getting input from USER");
break;
}
count++;
} while (x != 0 && count < 10);


System.out.println("Numbers from USER : " + userInputArray);
Collections.sort(userInputArray);
System.out.println("Numbers from USER : " + userInputArray);
} catch (InputMismatchException iex) {
System.out.println("Sorry You have entered a invalid input");
} catch (Exception e) {
System.out.println("Something went wrong :-( ");
}

}
}

Here is an example of what I want to display:

Numbers 10, 25, 3, 4,6, 30. 5, 7,1 are entered.

The program will display:

10 and 25
30 and 5

and the map: 10,25,3,4,6,30,5,7,1


I can get this result if I initialized the array.

But I cannot make it work with the scanner so I can enter different numbers every I run the program.

I am sorry for the confusion. But I just want to enter numbers, then display the pairs that will add up to 35. So I have the code working for displaying the pairs. I just cannot figure out how to make the user input scanner work. The Map is to display the pairs that add to 35. I appreciate your patience. Thanks

I want to enter numbers and then for numbers summing 35, I would like to display:

Found numbers : 20 and 15

Found numbers : 25 and 10

Found numbers : 30 and 5

out of user input:

15,5,10,20,25,30

But I am getting the error mentioned above.

Thanks

Hello,

I tried that too and I am getting the error below:

Enter 10 Numbers
2
Given Number is 2
4
Given Number is 4
30
Given Number is 30
5
Given Number is 5
1
Given Number is 1
7
Given Number is 7
8
Given Number is 8
3
Given Number is 3
4
Given Number is 4
5
Given Number is 5
Exception in thread "main" java.lang.NullPointerException
at Four.main(Four.java:42)
------------------The is the code now ------------------------


import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Map;
import java.util.Hashtable;
import java.util.Scanner;

class Four {


private static int[] intArray;
private static int sum = 35;


public static void main(String[] args) {


Scanner input = new Scanner(System.in);
System.out.println("Enter 10 Numbers ");
int count = 0;
int x;
try {
do {
x = input.nextInt();
if (x != 0) {
System.out.println("Given Number is " + x);

int[] intArray = new int[10];
intArray[0] = x;

} else {
System.out.println("Program will stop Getting input from USER");
break;
}
count++;
} while (x != 0 && count < 10);
} catch (InputMismatchException iex) {
System.out.println("Sorry You have entered a invalid input");
} catch (Exception e) {
System.out.println("Something went wrong :-( ");
}
Map<Integer, Integer> intMap = new Hashtable<Integer, Integer>();
for (int i=0; i<intArray.length; i++)
{
intMap.put(i, intArray[i]);
System.out.println("i " + i + " array " + +intArray[i]);

if(intMap.containsValue(sum - intArray[i]))
System.out.println("Found numbers : "+intArray[i] +" and "+(sum - intArray[i]));

}
System.out.println(intMap);

}
}

I made the change inArray[0] = x;

and I get the following error:

Enter 10 Numbers
10
Given Number is 10
Something went wrong :-(
Exception in thread "main" java.lang.NullPointerException
at Four.main(Four.java:41)

Hello,

It adds an int to the array. Why it cannot add an int? What is the statement to compile without errors?

Thanks in advance!

Hi,

Thank you for your help.

When I add the below code for the user input:

int count = 0;
int x;
try {
do {
x = input.nextInt();
if (x != 0) {
System.out.println("Given Number is " + x);
intArray.add(x);
} else {
System.out
.println("Program will stop Getting input from USER");
break;
}
count++;
} while (x != 0 && count < 10);


between: System.out.println("Enter 10 Numbers ");
and

for (int i=0; i<intArray.length; i++)

I get the message:

Cannot invoke add(int) on the array type int[];

To clarify more:

I would like to display the same result below but with user input:

THAT GIVES THE BELOW RESULT:
Found numbers : 20 and 15
Found numbers : 25 and 10
Found numbers : 30 and 5
{5=30, 4=25, 3=20, 2=15, 1=10, 0=5}