Accept Array Of Non-negative Integers And Return Second Largest Integer
May 22, 2015
Write a function that accepts an array of non-negative integers and returns the second largest integer in the array.
Return -1 if there is no second largest.
The signature of the function is int f(int[ ] a)
Examples:
if the input array isreturn{1, 2, 3, 4}3{{4, 1, 2, 3}}3{1, 1, 2, 2}1{1, 1}-1{1}-1{}-1
In the signature what I understood is, I should write my function with the given signature,
The return type is "int"
method name is "f"
parameter is "a" right ?
Writing my doubts beside the particular line in the code
public static void main() // In the answer why they didn't use the class ?
In main method why they didn't use parameters ?(String[] args)
{
a1(new int[]{1, 2, 3, 4}); // what is "a1" here is it array name ? this line initializing the array ?
a1(new int[]{4, 1, 2, 3});
a1(new int[]{1, 1, 2, 2});
a1(new int[]{1, 1});
a1(new int[]{1});
a1(new int[]{});
}
static int a1(int[] a) // what is "a" here parameter ? and "a1" is method name ? why they used the array name and method name same ?
{
int max1 = -1;
int max2 = -1;
for (int i=0; i<a.length; i++)
Write a method maxOccurrences that accepts a list of integers as a parameter and returns the number of times the most frequently occurring integer (the “mode”) occurs in the list. Solve this problem using a map as auxiliary storage.
I am practicing some basic recursion and I was trying to solve this problem
Write a method sumTo that accepts an integer parameter n and returns the sum of the first n reciprocals. In other words:
sumTo(n) returns: 1 + 1/2 + 1/3 + 1/4 + ... + 1/n
For example, the call of sumTo(2) should return 1.5. The method should return 0.0 if passed the value 0 and should throw an IllegalArgumentException if passed a value less than 0.
This is my attempt to do it , however my output is always a 0.0 , and i do not understand why :
public static double sumTo(int n ){ if(n<0){ throw new IllegalArgumentException(); } else if (n==0){ return 0.0;
-Create a main method declares and creates an integer array called nums that can hold 15 integers.
-Use a for loop to fill that array with multiples of 3: 0, 3, 6, 9, etc.
-Then use similar for loop to print each value in the array on one line, with each value separated by a single space.
-Compile and run the program to see the result:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
As you write other methods, you'll also modify the main method to make calls to them. The printArray MethodWrite a method called printArray that accepts an integer array as a parameter. This method does not return a value, and must be declared as static so that the main method can call it. Instead of printing the array in the main method, move that loop into this method. Call the printArray method from the main method. Compile and run the program to verify it prints the sam result as before.Add a println statement so that after printing the array values on one line, it then moves to the following line.Finally, modify the loop in the printArray method so that, instead of using a traditional for loop, it instead uses a for-each loop. Compile and run the program again.
Part III: More Array Methods
The linearSearch Method In lecture we looked at a method that performed a binary search on a sorted array. A much simpler (though much less efficient) search is a linear search, that simply starts at the front of the array and looks at each element in turn until it finds it or reaches the end.Create a method called linearSearch that accepts an integer array and a single int value as parameters. The goal of the method is to find the second parameter (the target) in the array. The method should return a single int representing the index of the target value. This method should not print any output itself. In this method, use a traditional for loop to scan through the elements in the array. As soon as you find the target value, return the index of that value.
If you scan through the entire array without finding the target value, return a -1.Modify the main method to call the linearSearch method and print the results. Call it twice, searching for the value 18 (which it should find) and the value 10 (which it should not). Including the previous activity, the output of the main method should now look similar to this:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
The index of 18 is 6
The index of 10 is -1
The sumArray Method
The sumArray method should take an integer array as a parameter and return a single integer representing the sum of all values in that array.Use a for-each loop to access each value in the array and compute a running sum. After the loop, return the total.Call the method from the main method, producing the following augmented output:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
The index of 18 is 6
The index of 10 is -1
The sum of this array is 315
The addValue Method...The addValue method should accept an integer array and a single int as parameters. The purpose of the method is to add the second parameter to EACH value in the array. The addValue method does not return a value, but the elements inside the array will be modified. Call the addValue method from the main method, adding 100 to each element in the array. Then call the printArray method again to see the modified array values:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
The index of 18 is 6
The index of 10 is -1
The sum of this array is 315 100 103 106 109 112 115 118 121 124 127 130 133 136 139 142
Test a Different Array..Finally, duplicate the content of the main method to perform similar tests on another array. Instead of filling it with multiples of 3, fill it with multiples of 4. And instead of using an array size of 15, use an array size of 20.Modify the values search for to include one that is in the array and one that isn't.Rerun the main method and carefully check the results.If you haven't been doing it all along (which you should), make sure the appropriate class and method documentation is included.When you're satisfied that all methods are working correctly, modify the main method to delete the second array tests.
I have a problem where I have to create random integers from 1 to n + 1. When the array is displayed I have to find the missing integer from the values that are displayed and show that value. I have to use O(n^2) and O(n) operations. I have created this code so far but I cannot figure out how to make my values display n + 1. It is only displaying values 1, 2, 3, 4 and 5 in random order. I also cannot figure out how to find the missing value. I have created a boolean displayed statement but can't determine how to use it in this code.
=Java import java.util.Random; public class Task6 { public static void main(String[] args) { int[] numbers = new int[7]; //create array of numbers Random random = new Random(); boolean displayed = false; //boolean value to determine if number was displayed
I want to use a method, which takes for example an int and also returns an integer. For example, if the the given integer is strong return a, if it is notstrong return b. How would you write that in a Code?
I want to use that in a more general way. I want to give a method mlong the value X of the type date and let it return an int. Type date consists of 3 int, one of them is the int month.
mlong should return an int depending on the X.moth. at the moment my code looks like this:
// File1: public class date { public int day; public int month; public int year; }
// File 2: public class monthlength { public int mlong(date X) { int t; t = X.month; if (t == 1 || t == 3 || t == 5 || t == 7 || t == 8 || t == 10 || t == 12) { return 31; } if(t == 4 || t == 6 || t == 9 || t == 11) {return 30;} } }
Write a program that finds both the largest and smallest of several integers. T. For example, a program that determines the winner and loser of a sales contest would input the number of units sold by each salesperson. The salesperson who sells the most units wins the contest; the salesperson who sells the least units loses the contest. Write a pseudocode program, then a Java program that inputs a series of 10 integers and determines and prints the largest integer and the smallest integer. Your program should use at least the following four variables: counter, number , largest and smallest. After i run the code i just get the largest input without the smallest .
This is my code :
import java.util.Scanner; // program uses scanner // main Class begins public class Largest12 { public static void main(String[] args) //main method begins { //Initial variables int counter = 0; // initiate counter int number=0 ;
Question - Given an specific integer and an array of integers, find and remove all occurrences of the given integer and return an amended array. I solved it. Here is my solution -
I have problems getting the right number of times for each number of the array. Here is my code:
public static void main(String[] args) { int[] a = { 3, 13, 5, 9, 13, 6, 9, 13, 2, 3 }; int num = 3; int count = numbers(a, num); for (int i = 0; i < a.length; i++) {
1. Create a program that will return the maximum and minimum numbers in the elements of ONE-dimensional integer array. Save it as MaxMin_OneDim.java
2. Create a program that will return the maximum and minimum numbers in the elements of each row in a TWO-dimensional integer array. Save it as MaxMin_TwoDim.java
3. Write a program PrintPattern which prompt a user to enter a number and prints the following patterns using nested loops (assumed user entered number is 8 output is:)
1 .... 87654321
12 .... 7654321
123 .... 654321
1234 .... 54321
12345 .... 4321
123456 .... 321
1234567 .... 21
12345678 .... 1
(Without the dots, i just put them to give spaces)
Here is a simple program on applets that is giving me a bit of headache since it cannot always display the two numbers that it is supposed to: the largest and smallest of the five input integers.....I cannot see where i went wrong, you can always create separately the HTML file to load the applet in an appletviewer of your won size.
* 23.6 (Largest and Smallest) Write an applet that reads five integers, determines which are the largest and smallest integers in the group and prints them. Draw the results on the applet. */ import java.awt.Graphics; import javax.swing.JApplet; import javax.swing.JOptionPane;
public static void main(String args[]) { Scanner in=new Scanner(System.in); System.out.println("Enter the Total Number of Integers:"); int totalInteger=in.nextByte(); long largest=0; for(int i=1;i<=totalInteger;i++) { System.out.println("Enter Integer-"+i+":");
[code]...
I want to get Index of that particular number in which Value is largest.
I am not sure what is happening with my code, but it is giving me a negative number. I am trying to write a program that calculates the product of the odd integers between 1 and 25. I messed with the program and as soon as you enter a number over 22, the end result is a negative number.
int total = 1; for (int i = 1; i <= 25; i += 2){ total *= i; } System.out.println("Product:" + total);
This program is supposed to accept an integer as an input and display the message that the number is even or odd. The main method calls a Boolean method. Write a method private static boolean iseven(int number and the message is printed from the Main method. This is what I have.
import java.util.Scanner; public class OddorEven { int number; public static void main(String[] args) { Scanner input = new Scanner(System.in);
[Code] ....
I know the message is not being printed from the Main method. I'm not sure how to do that.
I am attempting to write a program that accepts input of a positive integer, reports each digit and then the sum of all digits. This is what I have so far:
*/ package numbersum; import java.util.*; public class Week4NumberSum { static Scanner console = new Scanner(System.in); /** * @param args the command line arguments
[Code]...
It works if I enter 1234567891 (10 digits) Enter a positive integer: 1234567891 digit: 1 digit: 2 digit: 3 digit: 4 digit: 5 digit: 6 digit: 7 digit: 8 digit: 9 digit: 1
The sum of the digits is 46
But if I enter 11 digits, it fails:
Enter a positive integer: 123456789123 (12) Exception in thread "main" java.util.InputMismatchException: For input string: "123456789123" at java.util.Scanner.nextInt(Scanner.java:2123) at java.util.Scanner.nextInt(Scanner.java:2076) at week4numbersum.Week4NumberSum.main(Week4NumberSum. java:26)
java - Scanner error with nextInt() - Stack Overflow gives me some infor for InputMismatchException - which I find described as In order to deal with this exception you must verify that the input data of your application meet its specification. When this error is thrown, the format of the input data is incorrect and thus, you must fix it, in order for your application to proceed its execution.
I don't understand why the 10 digit integer is OK but the 11 or > digit integer is a mismatch.
I am attempting to write a program that reads a nonnegative integer and computes and prints its factorial. So far I have: Java Code: import java.util.Scanner;
public class Chapter3point37 { public static void main(String[] args) { Scanner input = new Scanner(System.in); int nonNegative = 5; int count=1; int product=1; int factor=1; System.out.println("Input a nonnegative integer: "); nonNegative = input.nextInt();
[code]...
how I should correctly prompt the user to input the values.
Write a java program to accept a string, float and an integer as command line arguments. String value should be displayed. Also the program should display the maximum value of two numbers. Use Integer.parseInt() and Float.parseFloat()
Basically i have a question ask me to write a program that read integer from keyboard until a negative number is entered, and then print out the max and min out of the number i have entered.
This is what i have done already which works, but i need to ignore the negative number when print out max and min...which i dont know how to do so. when i compile this program now it will always give me the negative number i enter at the end as minimum. which i need to ignore
Also if negative number is entered at once the program should print a error message say max and min are undefined.
public static void main(String[] args) {
Scanner in = new Scanner(System.in); int large = Integer.MIN_VALUE; int small = Integer.MAX_VALUE; while(true) { System.out.print("Enter a integer: "); int n = in.nextInt();
So I wrote a method that simply calculates the sum of all integers between 1 and a given integer n. The method works fine however, as n gets big the solution will have time and space problems. Some I'm just curious if there is a better method than my iterative one that would produce a better Big O value.
public static int sum(int n) { int total = 0; for (int i = 1; i <=n; i++) total += i; return total; }
Write a recursive Java method countDigitx that takes two integer numbers as input (a number n and digit x) and returns the number of times digits x occurs in number n:
For example if n=23242 and x=2 then the method should return 3 that is the number of times the number 2 found in n.
I want to use a method, which takes for example an int and also returns an integer. For example, if the the given integer is even return 1, if it is not even return 0. How would you write that in a Code?
I want to use that in a more general way. I want to give a method mlong the value X of the type date and let it return an int. Type date consists of 3 int, one of them is the int month.
mlong should return an int depending on the X.moth.
At the moment my code looks like this:
// File1:
public class date { public int day; public int month; public int year; }
// File 2:
public class monthlength { public int mlong(date X) { int t; t = X.month; if (t == 1 || t == 3 || t == 5 || t == 7 || t == 8 || t == 10 || t == 12) { return 31; } if(t == 4 || t == 6 || t == 9 || t == 11) {return 30;} } }
How do I code this without having the need to use iterator? Code a Java method that accepts an ArrayList of integers and an integer. The method should delete all elements in the array list exactly divisible by the integer and return the number of remaining elements.
