简单洗牌算法

一个简单高效的洗牌算法，C代码。

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/*
 * 每次随机抽取一张牌放入数组后部
 */
void shuffle(short *poker, short len) {

	int i;
	srand((unsigned)time(NULL));

	for ( i=len-1; i>=1; i-- ) {

		int k = rand()%(i);
		int x = poker[k];
		poker[k] = poker[i];
		poker[i] = x;

	}

}

int main(void) {

	short LEN = 54, i;
	short *poker = malloc(LEN);

	for ( i=0; i<LEN; i++ )
		poker[i] = i;

	shuffle(poker, LEN);

	for ( i=0; i<LEN; i++ )
		printf("%d ", poker[i]);

	free(poker);

	return EXIT_SUCCESS;
}