Java Implementation of Radix Sort div-bargali#623

Java Implementation of Radix Sort

Author: div-bargali

Java/Algorithms/Sorting-Algorithms/RadixSort.java

@@ -0,0 +1,75 @@
+//Radix Sort implementation
+import java.util.Scanner;
+import java.util.Arrays;
+
+class Radix {
+
+ // An utility function to find the maximum element 
+static int findMaxElement(int arr[], int n)
+{
+int mx = arr[0];
+for (int i = 1; i < n; i++)
+if (arr[i] > mx)
+mx = arr[i];
+return mx;
+}
+
+static void countingSort(int arr[], int n, int exp)
+{
+int output[] = new int[n];
+ int count[] = new int[10];
+ int i;
+Arrays.fill(count, 0);
+
+// Storing the count of all occurences
+for (i = 0; i < n; i++)
+count[(arr[i] / exp) % 10]++;
+
+// Change count[i] so that count[i] now contains actual position of this digit in output[]
+for (i = 1; i < 10; i++)
+count[i] += count[i - 1];
+
+// Building the output array
+for (i = n - 1; i >= 0; i--) {
+output[count[(arr[i] / exp) % 10] - 1] = arr[i];
+count[(arr[i] / exp) % 10]--;
+}
+
+//Copying contents back to arr from output array
+for (i = 0; i < n; i++)
+arr[i] = output[i];
+}
+
+//Performing Radix Sort
+static void radixsort(int arr[], int n)
+{
+// Finding the maximum number in the array to know the number of digits
+int m = findMaxElement(arr, n);
+
+//Implementing Counting sort for each digit
+for (int exp = 1; m / exp > 0; exp *= 10)
+countingSort(arr, n, exp);
+}
+ 
+ //Driver Function
+public static void main(String[] args)
+{
+ Scanner sc = new Scanner(System.in);
+
+ System.out.println("Enter the number of elements in the array - ");
+ int n = sc.nextInt();
+
+ int arr[] = new int[n];
+
+ System.out.println("Enter array elements - ");
+ for (int i = 0; i < n; i++)
+ arr[i] = sc.nextInt();
+
+ radixsort(arr, n);
+
+ for (int i = 0; i < n; i++)
+ System.out.print(arr[i] + " ");
+ 
+ sc.close();
+}
+}