how to implement radix sort java code example
Example 1: radix sort pseudocode
Radix-Sort(A, d)
for j = 1 to d do
int count[10] = {0};
for i = 0 to n do
count[key of(A[i]) in pass j]++
for k = 1 to 10 do
count[k] = count[k] + count[k-1]
for i = n-1 downto 0 do
result[ count[key of(A[i])] ] = A[j]
count[key of(A[i])]--
for i=0 to n do
A[i] = result[i]
end for(j)
end func
Example 2: radix sort pseudocode
import java.io.*;
import java.util.*;
class Radix {
static int getMax(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 countSort(int arr[], int n, int exp)
{
int output[] = new int[n];
int i;
int count[] = new int[10];
Arrays.fill(count,0);
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];
// Build the output array
for (i = n - 1; i >= 0; i--){
output[count[ (arr[i]/exp)%10 ] - 1] = arr[i];
count[ (arr[i]/exp)%10 ]--;
}
for (i = 0; i < n; i++)
arr[i] = output[i];
}
static void radixsort(int arr[], int n)
{ // Find the maximum number to know number of digits
int m = getMax(arr, n);
for (int exp = 1; m/exp > 0; exp *= 10)
countSort(arr, n, exp);
}
static void print(int arr[], int n)
{
for (int i=0; i<n; i++)
System.out.print(arr[i]+" ");
}
public static void main (String[] args)
{ int arr[] = {170, 45, 75, 90, 802, 24, 2, 66};
int n = arr.length;
radixsort(arr, n);
print(arr, n);
}
}
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