My research:
https://www.baeldung.com/java-indices-array-after-sorting
I’m using Java and not using any advanced concepts so far. What is the easiest way to do this?
My first question is - why do you want to track the index position of the unsorted values?
They’re names of employees so.
import java.util.*;
public class Example {
public static void main(String[] args) {
int[][] hours = {
{2, 4, 3, 4, 5, 8, 8},
{7, 3, 4, 3, 3, 4, 4},
{3, 3, 4, 3, 3, 2, 2},
{9, 3, 4, 7, 3, 4, 1},
{3, 5, 4, 3, 6, 3, 8},
{3, 4, 4, 6, 3, 4, 4},
{3, 7, 4, 8, 3, 8, 4},
{6, 3, 5, 9, 2, 7, 9}
};
int[] weeklyHrs = new int[hours.length];
for (int i = 0; i < hours.length; i++) {
for (int j = 0; j < hours[i].length; j++) {
weeklyHrs[i] = weeklyHrs[i] + hours[i][j];
}
}
for (int i = 0; i < weeklyHrs.length; i++) {
System.out.print("Employee" + i + ":" + weeklyHrs[i]);
System.out.println();
}
System.out.println();
int[][] wHTwoD = new int[8][2];
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 2; j++) {
if (j % 2 == 0) {
wHTwoD[i][j] = i;
} else {
wHTwoD[i][j] = weeklyHrs[i];
}
}
}
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 2; j++) {
System.out.print(wHTwoD[i][j]);
}
System.out.println();
}
for (int i = 0; i < weeklyHrs.length; i++) {
System.out.print(weeklyHrs[i] + " ");
}
}
public static void sort(int[] arr) {
int temp;
for (int i = 0; i < arr.length; i++) {
for (int j = i; j < arr.length; j++) {
if (arr[j] < arr[i]) {
temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
}
}
}
Here’s the code that might help you understand what am I upto.
I’ve not been taught how to sort a 2d array based on the second column value, so I won’t do that.
Now, my concern is basically the title.
1 Like
Sorry, still not following. Do you have a link to the problem you are solving?
Suppose the weekly hours for all employees are stored in a two-dimensional array. Each row records an employee’s seven-day work hours with seven columns. For example, the following array stores the work hours for eight employees. Write a program that displays employees and their total hours in increasing order of the total hours.
Suppose the weekly hours for all employees are stored in a two-dimensional array. Each row records an employee's seven-day work hours with seven columns. For example, the following array stores the work hours for eight employees. Write a program that displays employees and their total hours in increasing order of the total hours.
int[][] hours = {
{2, 4, 3, 4, 5, 8, 8},
{7, 3, 4, 3, 3, 4, 4},
{3, 3, 4, 3, 3, 2, 2},
{9, 3, 4, 7, 3, 4, 1},
{3, 5, 4, 3, 6, 3, 8},
{3, 4, 4, 6, 3, 4, 4},
{3, 7, 4, 8, 3, 8, 4},
{6, 3, 5, 9, 2, 7, 9}
};
Hours array looks like this.
I want to find:
-
total weekly hours of each employee.
-
and sort them in increasing order of work hours.
I can easily find the total weekly hours of each employee.
Like this:
for (int i = 0; i < hours.length; i++) {
for (int j = 0; j < hours[i].length; j++) {
weeklyHrs[i] = weeklyHrs[i] + hours[i][j];
}
}
Now, my concern is how do I track earlier indices. Since those indices are actually the employee id. I can’t change them like that.
So I thought why not use a 2d array instead of 1d array for weeklyHrs.
int[][] wHTwoD = new int[8][2];
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 2; j++) {
if (j % 2 == 0) {
wHTwoD[i][j] = i;
} else {
wHTwoD[i][j] = weeklyHrs[i];
}
}
}
I used a 2d array like this. But the concern now is to sort it based on column 1’s values i.e the hours.
Can anyone guide me how can I solve this problem?
import java.util.*;
public class Example {
public static void main(String[] args) {
int[][] wh2d = {
{0, 34},
{1, 28},
{2, 20},
{3, 31},
{4, 32},
{5, 28},
{6, 37},
{7, 41}
};
boolean isSwapped = false;
int k = 0;
for (int i = 0; i < wh2d.length; i++) {
for (int j = wh2d[i].length - 1; j >= 0; j--) {
// do sort if j%2==0
// sort wh2d[i][j]
if (j == 1) {
// sort it
for (k = i + 1; k < wh2d.length; k++) {
if (wh2d[i][j] < wh2d[k][j]) {
// swap
int temp = wh2d[i][j];
wh2d[i][j] = wh2d[k][j];
wh2d[k][j] = temp;
isSwapped = true;
// swap the corresponding indices
int temp2 = wh2d[i][0];
wh2d[i][0] = wh2d[k][0];
wh2d[k][0] = temp2;
}
}
}
}
}
for (int i = 0; i < wh2d.length; i++) {
for (int j = 0; j < wh2d[i].length; j++) {
System.out.print(wh2d[i][j] + " ");
}
System.out.println();
}
}
}
I’ve solved it lol. too hardcoded though.
That is one way to do it! The way I might do this would be to create a new array that stores two values:
[“emp0”, totalHours]
[“emp1”, totalHours]
[“emp2”, totalHours]
This will make the sorting much MUCH easier.
