Question

Please help me with this algorithm assignment using Java

Write 2 functions to calculate the MSS of a given array one with running time of O(n) and one with O(nlogn) .Request the user to enter a positive integer, and call it n.

1.Generate n random integers between -100 to 100 and save them in array a.

2.Print the generated array and the outputsof your two functions

Answer 1

Solution:

code:

package abc

import java.util.Random;
import java.util.Scanner;
public class MSS {
/**
* @param args
*/
public static void main(String[] args) {
Scanner userInput = new Scanner(System.in);
Random random = new Random();
int low = -100;
int high = 100;
System.out.println("Enter positive integer: ");
int n = userInput.nextInt();
int arr[] = new int[n];
for (int i=0;i<n;i++) {
int randomNumber = random.nextInt(high - low) + low;
arr[i] = randomNumber;
}
System.out.println("Original Array: ");
printArray(arr);
sort(arr,0,arr.length-1);
userInput.close();
System.out.println("Sorted Array: ");
printArray(arr);
}
public static void sort(int arr[], int l, int r) {
if (l < r) {
// Find the middle point
int m = (l + r) / 2;
// Sort first and second halves
sort(arr, l, m);
sort(arr, m + 1, r);
// Merge the sorted halves
merge(arr, l, m, r);
}
}
public static void merge(int arr[], int l, int m, int r) {
// Find sizes of two subarrays to be merged
int n1 = m - l + 1;
int n2 = r - m;
/* Create temp arrays */
int L[] = new int[n1];
int R[] = new int[n2];
/* Copy data to temp arrays */
for (int i = 0; i < n1; ++i)
L[i] = arr[l + i];
for (int j = 0; j < n2; ++j)
R[j] = arr[m + 1 + j];
/* Merge the temp arrays */
// Initial indexes of first and second subarrays
int i = 0, j = 0;
// Initial index of merged subarry array
int k = l;
while (i < n1 && j < n2) {
if (L[i] <= R[j]) {
arr[k] = L[i];
i++;
} else {
arr[k] = R[j];
j++;
}
k++;
}
/* Copy remaining elements of L[] if any */
while (i < n1) {
arr[k] = L[i];
i++;
k++;
}
/* Copy remaining elements of R[] if any */
while (j < n2) {
arr[k] = R[j];
j++;
k++;
}
}
public static void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
}

Output:

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