퀵정렬 구현

1 C

#include <stdio.h>
#define SIZE 10
int arr[SIZE] = {3,4,2,1,7,5,8,9,0,6};
void swap(int i, int j) {
	int temp = arr[i];
	arr[i] = arr[j];
	arr[j] = temp;
}
int partition(int left, int right, int pivot) {
	int original_right = right;
	while(1) {
		while( arr[++left] < pivot ) {}
		while( right>0 && arr[--right]>pivot ) {}
		if( left >= right ) break;
		swap( left, right );
	}
	swap( left, original_right );
	return left;
}
void quick_sort(int left, int right) {
	if(right-left <= 0) return;   
	int partition_point = partition(left-1,right,arr[right]);
	quick_sort( left, partition_point-1 );
	quick_sort( partition_point+1, right );
}
int main() {
	quick_sort(0,SIZE-1);
	for(int i=0; i<SIZE; i++) printf("%d ",arr[i]);
	// 0 1 2 3 4 5 6 7 8 9 
}

2 Java

Java 퀵정렬 구현 문서를 참고하십시오.

public class MyClass {
    static void quickSort(int arr[]) {
        quickSort(arr, 0, arr.length-1);
    }
    static void quickSort(int a[], int L, int R) {
        int left, right, pivot=a[L];
        for(left=L,right=R; left<right; right--) {
            while( a[right]>=pivot && left<right ) right--;
            if( left<right ) a[left] = a[right];
            while( a[left]<=pivot && left<right ) left++;
            if( left>=right ) break;
            a[right] = a[left];
        }
        a[left]=pivot;
        if(left>L) quickSort(a, L, left-1);
        if(left<R) quickSort(a, left+1, R);
    }
    public static void main(String[] args) {
        int[] arr = {9,1,22,4,0,-1,1,22,100,10};
        quickSort(arr);
        for(int x:arr) System.out.format( "%d ", x );
        // -1 0 1 1 4 9 10 22 22 100 
    }
}

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