基數排序

import java.math.* ;
import java.util.* ;

/**
 * 
 */
public class Test extends Base{
	public static void main(String[] args) throws Exception{
		int[] arr = getRandomArr() ;
		println(arr);  
		radixSort(arr , arr.length );
		println(arr);
		println();		
	}

	public static void radixSort(int[] arr, int n ){
		int BASE = 10 ;
		int exp = 1 ;
		int[] radix = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0} ;
		int[] temp = new int[n] ;
		int max = arr[0] , r = 1;
		for (int i = 1 ; i < n; i++){
			if(arr[i] > max) max = arr[i] ;
		} 
		int pos , div = 1;
		while(max/exp > 0){ 
			for (int i = 0 ; i < n ; i++){ 
				radix[(arr[i] / exp) % BASE] += 1; 
			} 
			for (int i = 1 ; i < n ; i++){
				radix[i] += radix[i-1] ;
			} 
			for (int i = n - 1 ; i >= 0 ; i--){
				radix[(arr[i] / exp) % BASE] -= 1;
				temp[radix[(arr[i] / exp) % BASE]] = arr[i] ; 
			}  
			for (int i = 0 ; i < n ; i++ ){
				arr[i] = temp[i] ;
			} 
			for (int i = 0 ; i < BASE ; i++){
				radix[i] = 0 ;
			}

			exp *= BASE ;
		}
	}

}