c語言裏面用rand()函數產生無重復的0-15的隨機數

#include <stdio.h>

#include <stdlib.h>

main()

{

int seed=1000; // 種子

int i;

int m[16] ;

int nn=0;

double r;

printf("enter seed please\n");

scanf("%d",&seed);

srand(seed); // 初始化隨機數生成器

for (i=0;i<=15;i++) m[i] = 0;

while (nn < 10 ){

// r 是雙精度浮點隨機數,範圍0.0到1.0

r = ( (double)rand() / ((double)(RAND_MAX)+(double)(1)) );

i =(int) ( r * 15.0);

if (m[i] == 0) {

m[i] = 1; nn = nn + 1;

printf("%d ",i);

};

}

}