how order number from larg to small

Question

In java
Pleas help me

Answer 1

int[] array = new int[]{8,5,3,7,9,12,4,1};
int max = Arrays.stream(array).max().getAsInt();

Answer 2

// Selection sort algorithm (slow, but easiest to implement)

import java.util.Arrays;

public class SelectionSort
{
public static void main(String[] args) {
int[] arr = {5, 7, 4, 2, 1, 0, 9};

for (int i = 0; i < arr.length - 1; i++) {
for (int j = i + 1; j < arr.length; j++) {
if (arr[i] < arr[j]) {
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
}
System.out.println(Arrays.toString(arr));
}
}

Answer 3

Using Mergesort algorithm:

class MergeSort {
static void merge(int arr[], int l, int m, int r) {
int n1 = m-l+1;
int n2 = r-m;

int L[] = new int [n1];
int R[] = new int [n2];

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];

int i = 0, j = 0;
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++;
}
while (i < n1) {
arr[k] = L[i];
i++;
k++;
}
while (j < n2) {
arr[k] = R[j];
j++;
k++;
}
}
static void MergeSort(int arr[], int l, int r) {
if (l < r) {
int m = (l+r)/2;
MergeSort(arr, l, m);
MergeSort(arr, m+1, r);
merge(arr, l, m, r);
}
}

public static void main(String args[]) {
int arr[] = {10, 54, 63, 6, 420};

MergeSort(arr, 0, arr.length-1);

for(int i=0; i<arr.length; i++)
System.out.print(arr[i]+" ");
}
}