2DArray

/*
* Hailey Martin
* Description:
* This program will manipulate arrays by filling them with
* random values and performing operations (sum, average
* median, finding largest value, and the number of times
* the largest value occurs in the array)on the array. The 
* 1D array values will also be placed into a 2D array. This 
* program will also read and write the 2D array to and from 
* a file.
*/
 
import java.io.IOException;
import java.util.Arrays;
import java.io.File;
import java.io.PrintWriter;
import java.util.Scanner;
 
public class MartinHaileyAssignment1 {
 
public static void main(String[] args)throws IOException {
// TODO Auto-generated method stub
 
//Task #1 fill  array with 20 random integers between 10 and 40
final int MAX = 40;
final int MIN = 10;
final int NUM_OF_INTS = 20;
int [] array = new int [NUM_OF_INTS];
//generate random integers to array
for(int i=0; i<array.length; i++) {
array[i] += (int)(Math.random()*(MAX-MIN + 1)+ MIN);
System.out.println(array[i]);
}
//Task #2 calculate sum, average, median, largest value
//and the number of times that value appears in the array
//find average and sum
double sum = 0;
for(int i=0; i<array.length; i++) {
sum += array[i];
}
double average = sum/ array.length;
System.out.printf("\nSum = %.1f \nAverage = %.1f\n",sum, average);
//find median
//sort array
for(int i= 0; i< array.length; i++) {
Arrays.sort(array);
}
//if required output wanted the median to show as a double this equation could
//be explicitly casted with double to give more accuracy
int median = ((array[(array.length-1)/2]) + (array[(array.length+1)/2])) / 2;
System.out.printf("Median = %d", median);
//find largest value and how many times it occurs in the array
int largestValue = 0;
//check array for largest value
for(int i=0; i<array.length; i++) {
if(array[i]> largestValue) {
largestValue = array[i];
}
}
System.out.printf("\nLargest value = %d ",largestValue);
int largestValueCount = 0;
//check array for the number of times the largest value appears
for(int i=0; i< array.length; i++) {
if(array[i] == largestValue) {
largestValueCount++;
}
}
System.out.printf("which occured %d times\n", largestValueCount);
System.out.println();
//Task #3 put 1D array values into a 2D array
final int NUM_ROWS = 4;
final int NUM_COLS = 5;
int[][] intArray = new int[NUM_ROWS][NUM_COLS];
 
//insert values from 1D array to 2D array 
int count =0;
//loop through 2D array and assign 1D array value using count as array index
for(int row=0; row<NUM_ROWS; row++) {
for(int col=0; col<NUM_COLS; col++) {
intArray[row][col] = array[count];
count++;
}
}
//display 2D array
System.out.println("Values placed into 2D array");
for(int row=0; row<NUM_ROWS; row++) {
for(int col=0; col<NUM_COLS; col++) {
System.out.print(intArray[row][col] + " ");
}
System.out.println();
}
//Task#4 create file, open file, write file,
//close file and reopen to read file
File fileName = new File("assignment1.txt");
PrintWriter outputFile = new PrintWriter(fileName);
//write 2D array to file
for(int row=0; row<NUM_ROWS; row++) {
for(int col=0; col<NUM_COLS; col++) {
outputFile.write(intArray[row][col] +"\n");
}
}
outputFile.close();
Scanner readFile = new Scanner(fileName);
System.out.println("\nRandom values stored in file in sorted order");
//read and display file
for(int row=0; row<NUM_ROWS; row++) {
for(int col=0; col<NUM_COLS; col++) {
System.out.print(readFile.next());
System.out.println("");
}
}
readFile.close();
//where to find file
System.out.println("\nFile is in directory: " + fileName.getAbsolutePath());
}//end of main
 
}