排序算法——计数排序【代码实现】
伪代码
function countingSort(array, min, max):
count: array of (max - min + 1) elements
initialize count with 0
for each number in array do
count[number - min] := count[number - min] + 1
done
z := 0
for i from min to max do
while ( count[i - min] > 0 ) do
array[z] := i
z := z+1
count[i - min] := count[i - min] - 1
done
done
ActionScript
function countingSort(array:Array, min:int, max:int)
{
var count:Array = new Array(array.length);
for(var i:int = 0; i < count.length;i++)count[i]=0;
for(i = 0; i < array.length; i++)
{
count[array[i]-min] ++;
}
var j:uint = 0;
for(i = min; i <= max; i++)
{
for(; count[i-min] > 0; count[i-min]--)
array[j++] = i;
}
return array;
}
C
#include C++
#include C#
using System;
using System.Linq;
namespace CountingSort
{
class Program
{
static void Main(string[] args)
{
Random rand = new Random(); // Just for creating a test array
int[] arr = new int[100]; // of random numbers
for (int i = 0; i < 100; i++) { arr[i] = rand.Next(0, 100); } // ...
int[] newarr = countingSort(arr, arr.Min(), arr.Max());
}
private static int[] countingSort(int[] arr, int min, int max)
{
int[] count = new int[max - min + 1];
int z = 0;
for (int i = 0; i < count.Length; i++) { count[i] = 0; }
for (int i = 0; i < arr.Length; i++) { count[arr[i] - min]++; }
for (int i = min; i <= max; i++)
{
while (count[i - min]-- > 0)
{
arr[z] = i;
z++;
}
}
return arr;
}
}
}
Go
package main
import (
"fmt"
"runtime"
"strings"
)
var a = []int{170, 45, 75, -90, -802, 24, 2, 66}
var aMin, aMax = -1000, 1000
func main() {
fmt.Println("before:", a)
countingSort(a, aMin, aMax)
fmt.Println("after: ", a)
}
func countingSort(a []int, aMin, aMax int) {
defer func() {
if x := recover(); x != nil {
// one error we'll handle and print a little nicer message
if _, ok := x.(runtime.Error); ok &&
strings.HasSuffix(x.(error).Error(), "index out of range") {
fmt.Printf("data value out of range (%d..%d)\n", aMin, aMax)
return
}
// anything else, we re-panic
panic(x)
}
}()
count := make([]int, aMax-aMin+1)
for _, x := range a {
count[x-aMin]++
}
z := 0
// optimization over task pseudocode: variable c is used instead of
// count[i-min]. This saves some unneccessary calculations.
for i, c := range count {
for ; c > 0; c-- {
a[z] = i + aMin
z++
}
}
}
Java
public static void countingSort(int[] array, int min, int max){
int[] count= new int[max - min + 1];
for(int number : array){
count[number - min]++;
}
int z= 0;
for(int i= min;i <= max;i++){
while(count[i - min] > 0){
array[z]= i;
z++;
count[i - min]--;
}
}
}
JavaScript
var countSort = function(arr, min, max) {
var i, z = 0, count = [];
for (i = min; i <= max; i++) {
count[i] = 0;
}
for (i=0; i < arr.length; i++) {
count[arr[i]]++;
}
for (i = min; i <= max; i++) {
while (count[i]-- > 0) {
arr[z++] = i;
}
}
}
Kotlin
// version 1.1.0
fun countingSort(array: IntArray) {
if (array.isEmpty()) return
val min = array.min()!!
val max = array.max()!!
val count = IntArray(max - min + 1) // all elements zero by default
for (number in array) count[number - min]++
var z = 0
for (i in min..max)
while (count[i - min] > 0) {
array[z++] = i
count[i - min]--
}
}
fun main(args: Array<String>) {
val array = intArrayOf(4, 65, 2, -31, 0, 99, 2, 83, 782, 1)
println("Original : ${array.asList()}")
countingSort(array)
println("Sorted : ${array.asList()}")
}
Perl
#! /usr/bin/perl
use strict;
sub counting_sort
{
my ($a, $min, $max) = @_;
my @cnt = (0) x ($max - $min + 1);
$cnt[$_ - $min]++ foreach @$a;
my $i = $min;
@$a = map {($i++) x $_} @cnt;
}
PHP
function counting_sort(&$arr, $min, $max)
{
$count = array();
for($i = $min; $i <= $max; $i++)
{
$count[$i] = 0;
}
foreach($arr as $number)
{
$count[$number]++;
}
$z = 0;
for($i = $min; $i <= $max; $i++) {
while( $count[$i]-- > 0 ) {
$arr[$z++] = $i;
}
}
}
PowerShell
function countingSort($array) {
$minmax = $array | Measure-Object -Minimum -Maximum
$min, $max = $minmax.Minimum, $minmax.Maximum
$count = @(0) * ($max - $min + 1)
foreach ($number in $array) {
$count[$number - $min] = $count[$number - $min] + 1
}
$z = 0
foreach ($i in $min..$max) {
while (0 -lt $count[$i - $min]) {
$array[$z] = $i
$z = $z+1
$count[$i - $min] = $count[$i - $min] - 1
}
}
$array
}
$array = foreach ($i in 1..50) {Get-Random -Minimum 0 -Maximum 26}
"$array"
"$(countingSort $array)"
Python
Follows the spirit of the counting sort but uses Pythons defaultdict(int) to initialize array accesses to zero, and list concatenation:
>>> from collections import defaultdict
>>> def countingSort(array, mn, mx):
count = defaultdict(int)
for i in array:
count[i] += 1
result = []
for j in range(mn,mx+1):
result += [j]* count[j]
return result
>>> data = [9, 7, 10, 2, 9, 7, 4, 3, 10, 2, 7, 10, 2, 1, 3, 8, 7, 3, 9, 5, 8, 5, 1, 6, 3, 7, 5, 4, 6, 9, 9, 6, 6, 10, 2, 4, 5, 2, 8, 2, 2, 5, 2, 9, 3, 3, 5, 7, 8, 4]
>>> mini,maxi = 1,10
>>> countingSort(data, mini, maxi) == sorted(data)
True
Ruby
class Array
def counting_sort!
replace counting_sort
end
def counting_sort
min, max = minmax
count = Array.new(max - min + 1, 0)
each {|number| count[number - min] += 1}
(min..max).each_with_object([]) {|i, ary| ary.concat([i] * count[i - min])}
end
end
ary = [9,7,10,2,9,7,4,3,10,2,7,10,2,1,3,8,7,3,9,5,8,5,1,6,3,7,5,4,6,9,9,6,6,10,2,4,5,2,8,2,2,5,2,9,3,3,5,7,8,4]
p ary.counting_sort.join(",")
# => "1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,4,4,4,4,5,5,5,5,5,5,6,6,6,6,7,7,7,7,7,7,8,8,8,8,9,9,9,9,9,9,10,10,10,10"
p ary = Array.new(20){rand(-10..10)}
# => [-3, -1, 9, -6, -8, -3, 5, -7, 4, 0, 5, 0, 2, -2, -6, 10, -10, -7, 5, -7]
p ary.counting_sort
# => [-10, -8, -7, -7, -7, -6, -6, -3, -3, -2, -1, 0, 0, 2, 4, 5, 5, 5, 9, 10]
更多代码，敬请期待！
整理自网络。