Recursion Method With 2d Array To Find A Column With Lowest Sum
Jan 28, 2015
i have to write a method, The method receives a parameter of two-dimensional array of integers. The method returns the number of the column which has the lowest sum of the integers.I'm allowed to use only recursion! no loops allowed!-of course i need to make a private method that will sum a column as a single array and then i have to do another private method that compares the column , but it doesn't really work .
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Jan 5, 2015
I am not getting the result I am looking for, but I'm sure I'm on the right track. I have an array, names + times of marathon runners, and should end up with a program that displays the slowest runner, and the next-slowest runner.
Currently, I get this:
The lowest time is 273.
The lowest time is 243.
Changing names.length to times.length changes nothing.
for (i = 1;... ) changes nothing.
The displayed number should currently only be 243. Why is it displaying 273 first, and at all?
The code:
class Marathon {
public static void main (String[] arguments) {
String[] names = {"Elena", "Thomas", "Hamilton", "Suzie", "Phil", "Matt", "Alex", "Emma", "John", "James", "Jane", "Emily", "Daniel", "Neda", "Aaron", "Kate"};
int[] times = {341, 273, 278, 329, 445, 402, 388, 275, 243, 334, 412, 393, 299, 343, 317, 265};
int min = times [0];
for (int i = 0; i < times.length; i++) {
if (times[i] < min){
min = times[i];
System.out.println("The lowest time is " + min +".");
}
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Oct 26, 2014
import java.io.IOException;
public class Largestcolumn
{
public static void main ( String[] args ) throws IOException
{
int largest = 0;
int newnumber = 0;
int[][] data = { {3, 2, 5},
[Code] ....
When I run this code, I get this following output: The largest element in column 0 is: 9.
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
at largestcolumn.Largestcolumn.main(Largestcolumn.java:27)
Java Result: 1
It outputs the first column's maximum element but then throws an out of bounds error. I'm new to Java and I can't figure out how to fix my code so that it will work for this multidimensional array and output the maximum elements in all of the columns.
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Mar 9, 2015
so i have this question where it wants me to create a recursion method that takes ONLY THE ARRAY as a parameter, and without using loops or static variables inside the method, and then the method returns the smallest value in that array. However, i tried making the simple if statements where i compare the first element of the array with the second element using the length of the array and decreasing it to get the next elements and compare it again by calling the recursion method, but the problem is when i call the method again, the length does not decrease, even if i store it in a variable, the variable will initialize itself again, and the length wont change.
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Feb 2, 2015
I am trying to sum up the elements of an array. When I test my code the sum is always off by one. For example if I input: 20, 40,30 it gives me 89 instead of 90.
This is what I have so far:
public static void main(String[args]){
int size = kbd.nextInt();
int [] myArray = new int [size]
//user inputs the elements of array
[Code]....
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Apr 12, 2014
I have to find the average, highest, and lowest numbers in an array. I already have the average and highest, and I thought I could find the lowest number the same way I found the highest, but it's not working. It just keeps coming out to 0. I've tried out different ways, but I want to see if there are better ways than doing MAX_VALUE for the lowest, then looping it through.
import java.util.Scanner;
public class Test_Scores {
public static void main(String[] args) {
//array,scanner,values
[Code].....
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May 2, 2014
Java program takes positive int from user and determine if prime. Next the program finds next highest or next lowest prime number.
import java.io.*;
import java.util.*;
public class pa2take2 {
public static void main (String[]args){
int menus; //menu selection
[Code] ......
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Dec 5, 2014
I made a method which takes values from a data set and finds out which one is the highest value. When it finds the highest value, it returns the country which is associated with the value. Here's the data set.
"Country""Total CO2 2005 (million tonnes)""Road CO2 (million tonnes)""Road CO2 per person (tonnes)""Cars per 1000 people"
10
USA5951.131530.35.16777
UK2573.4119.681.99470
Italy476.08116.862592
Germany841.78150.211.82550
Canada553.02123.423.82562
France414.03128.132.04477
Russia1575.44114.690.8178
Japan1254.47224.241.76447
China5100.6228.020.317
India1147.4691.060.18
So if the number was 5951.13 then the program would return USA. How do I do that? I've already started on trying to get this code to work but it doesn't seem to compiler so what's wrong with it?
public static CO2Data highest (CO2Data [] arr2){
Scanner sc = new Scanner(System.in);
CO2Data highestindex = arr2[0];
CO2Data currentcountry = arr2[0].getCountry(sc.nextLine());
[Code] ....
Also the array is a CO2Data array which is part of the following class:
public class CO2Data { //The CO2Data class will be called in other methods
private String country; //A private variable will prevent other users from accessing and changing these variables.
private double totalCO2;
private double roadCO2;
private double CO2PerPerson;
private int carsPerPerson;
public CO2Data() {
country = "";//this sets the initial values for the different variables
[code].....
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May 14, 2014
We are required to write a binary‐search method to find an int within an array of ints. Without using any functions besides the basics (for loops, if statements, etc.)
I have this so far:
public int binarySearch(int[] ints, int n) {
for(int i = 0; i < ints.length; i++) {
if(ints[i] == n) {
return ints[i];
}
}
}
Does this look somewhat correct?
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Jan 14, 2014
i want to write a program have a array 2d like that :
int array [][] = new int [3][3]
after that the user input value by using scanner then give summation of each column in matrix , i wrote this one
Java Code:
class MatrixSum{
public static void main(String[] args) {
int matrix1[][]= {{7,8,9},{1,5,2}};
int matrix2[][]= {{1,6,4},{2,7,3}};
System.out.println("Number of Row= " + matrix1.length);
System.out.println("Number of Column= " + matrix1[1].length);
int l = matrix1.length;
System.out.println("Matrix 1 : ");
for(int i = 0; i < l; i++) {
[code]...
but i want to change that the user input the value by using scanner.
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Feb 13, 2015
So I have this code to calculate the lowest value of an array:
public class Exercise1 {
public static void main(String[] args) {
int[] theArray = {1/*/,2,3,4,5,6,7,8,9,10/*/};
int result = Exercise1.min(theArray);
System.out.println("The minimum value is: " +result);
[code].....
and I need to write an exception class that should be thrown if the array does not hold any elements.
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Aug 12, 2014
I am trying to return the lowest value from the array. having trouble trying to capture the return value by placing it into the variable ..
int myLowest = getLowest(yourNumbers); and then printing out myLowest
import java.util.*;
public class numArrays
{
public static void main(String[] args){
int numbers;
int[]yourNumbers;
[code]....
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Apr 5, 2014
I am attempting to find the element that holds the lowest time ( i have used System.currentMillisTime ) in the array using a linear search and to then print the times held by the array in lowest to highest order . While i understand how to do a linear search using user input as the key i am not to sure how to do it by initializing a search key in the program to the lowest number and have little experience in using a search in a program that is not a simply linear search. i have attempted to code this, as seen below, but i know i am definitely wrong and i have tried another of different ways even Array.sort and then a binary search .
static long store_MAX[]; // Now an ‘array’ of ints
static int deptSize; // Holds the length of the buffer
private int shopper_MAX; // Holds the number of items in the buffer
[Code].....
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Feb 14, 2015
code a 10 * 10 matrix, with random numbers from 1 to 100,
i) Find the most repeated number.
ii) Use the Binary Sort, to sort the matrix in ascending order.
iii) Find the Column, with the highest average number.
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Nov 6, 2014
We are supposed to create a MergeSort method without the using recursion. Most of the code is already completed, the only thing that I believe I need are two for loops (an inner and an outter) that will make calls to the merge method. I need implementing the sort method of the merge sort algorithm without recursion, where the length of the array is a power of 2. Keep merging adjacent regions whose size is a power of 2. For ex: lengths will be 1, 2, 4, 8, 16,.
public class MergeSorter {
public static void sort(int[] a) {
//for(int i = 1; i <= a.length; i++) the parameters for the for loop are wrong.
{
merge(0,0,1,a);
merge(1,1,2,a);
merge(2,2,3,a);
[Code]...
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Jan 11, 2015
i'm trying to exit the recursion of a void method but some funny things are happening before and after the return statement.
public static void main(String args[])
{
//code
rec(x,y);
System.out.println("HEllooooooo");}
public static void rec(int x,int y)
{
try
{
System.out.println(x+" "+y+" "+check);
if(x==fx && y==fy)
[code]....
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Mar 25, 2015
How to add the sum of an array with a recursion, but I don't understand how to use recursion. I just understand that it calls back the method. I am nearly done with the code.
import java.util.Scanner;
class Question1{
public static void main(String[]args){
Scanner s = new Scanner(System.in);
int size, sum;
System.out.println("Please input how many numbers will be used");
size=s.nextInt();
[Code] .....
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Apr 15, 2015
In this project each individual will create a data analysis program that will at a minimum,
1) read data in from a text file,
2) sort data in some way,
3) search the data in some way,
4) perform at least three mathematical manipulations of the data,
5) display results of the data analysis in numeric/textual form, and
6) display graphs of the data. In addition,
7) your program should handle invalid input appropriately and
8) your program should use some "new" feature that you have not been taught explicitly in class.
(Note: this is to give you practice learning new material on your own - a critical skill of today's programmer.) If you do not have a specific plan in mind for your project, below is a specific project that meets all of the qualifications as long as 7) and 8) are addressed in the implementation.
Everything is done except I need to call my methods in my GradeTester.
GradeBook:
/**
*This class creates an array called scores.
*This class determines the length of the array scores and determines the last grade in the array scores.
*This class sorts the array using a bubble sort, and searches the array.
*This class calculates the mean, standard deviation, and the median of the grades in the array scores.
*Once the grades in the array is sorted, the class then calculates the highest and lowest grades in the array.
*/
public class GradeBook {
public final int MAXARRAY_SZ = 20;
double [] scores = new double [MAXARRAY_SZ];
int lastGrade = 0;
double mean = 0;
[Code] ....
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Feb 26, 2014
I have this method
Java Code:
public static int[] oddNums(int n){
} mh_sh_highlight_all('java');
When a number is passed in, this method returns an array of odd numbers the amount of the number passed in.
So
Ex: Class.oddNums(5) would return [ 1, 3, 5, 7, 9 ]
Class.oddNums(2) would return [ 1, 3]
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Nov 1, 2014
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;
[Code] .....
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Feb 2, 2015
I am trying to sum up the elements of an array. When I test my code the sum is always off by one. For example if I input: 20, 40,30 it gives me 89 instead of 90.
This is what I have so far:
public static void main(String[args]){
int size = kbd.nextInt();
int [] myArray = new int [size]
//user inputs the elements of array
for(int i =0; i<myArray.length; i++){
myArray[i]= kbd.nextInt();
}
int total = sumNum(myArray,0, myArray.length-1)
System.out.println("The sum is"+ total);
}
[code]....
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Sep 28, 2014
I need to add a column to my array and copy an old array and then fill the new array with another array..However, unfortunately it does not work. I found this code online..but it seems it does not work.
static float[][] temperatures = new float[5][6];
static float[] d=new float[5];
float[][] neww;
int am,am1,am2,am3,res1,res2;
public static void main(String[] args) {
float[][] neww= Arrays.copyOf(temperatures, temperatures.length+1);
neww[temperatures.length]= new float[temperatures.length];
for (int i = 0; i < temperatures.length; i++) {
neww[temperatures.length][i] = Float.valueOf(d[i]);
}
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Mar 13, 2015
import java.util.Scanner;
public class ColumnSum {
public static void main(String[] args) {
Scanner s = new Scanner (System.in);
int userpick = 0;
int sum = 0;
int [][] matrix = {{5, 9, 87, 74, 12, 7}, // row 1
[code]...
Right now my code gets all the numbers in a row and adds those up, but I want it to get the numbers in a column and add them instead. The problem is I don't know how to get the userpick (the number that the user picks to determine which column gets added) to be set to that particular column.
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Feb 16, 2015
I've setup an array that I would like to analyze by adding up the contents of each column, however, the out of bounds exception pops up when I try to execute the program. I know the book usually expresses this operation the other way around, where the row is the argument of the first for statement, but I've set my array up where I need to add each row before moving to the next column.
vowelCounter is a 5x3 array.
// Display the line which had the most number of vowels
public static int maxVowelSentence() {
int max = 0, sum = 0;
int sentence = 1;
for (int row = 0; row < vowelCounter.length; row++) {
max = vowelCounter[row][0];
[Code] ....
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Mar 24, 2015
I am taking the Class Algorithms and Datastructures and got an assignment for Lab that really throws me off. The goal is to create an Array out of a given CSV file, implement several Methods that get the size of array, etc.
I am still stuck in the first part where the CSV has to be imported into the Array. My problem is that I need a mechanism that figures out the needed size for the Array, creates the array, and only then transfers the data from the CSV.
The list consists of the following wifi related values:
MAC-Adress, SSID, Timestamp, Signalstrength.
These are on the list, separated by comma. The Columns are each of these, and the rows are the four types of values making up the information on a certain wifi network.
The catch is, we are not allowed to use any of the following:
java.util.ArrayList
java.util.Arrays
and any class out of java.util.Collection.
So far I used the BufferedReader to read in the file and tried to implement the array, but I get an arrayindexoutofboundsexception.
Below is my Code (Its still an active construction zone):
public class WhatsThere {
public WhatsThere(String wifiscan) throws IOException {
}
public static void main(String[] args) throws IOException {
// WhatsThere Liste = new WhatsThere(String wifiscan);
String[][] arrayListe = new String[0][0];
[Code] ....
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Apr 10, 2014
I was given the Java code for a project and I am supposed to build unit tests to test the performance of seven sorting algorithms and I am getting the following error in my Lab1Test file...cannot find symbol: method sorta(int[]) location: class Lab1Test.
Lab1.java
Java Code: package funcollege.comp10062.perflib;
import java.text.DecimalFormat;
import java.util.Arrays;
import java.util.Random;
[code]...
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