math.c

来自「SimpleGraphicOperatingSystem 32位图形化操作系统 」· C语言 代码 · 共 33 行

#include <Osdef.h>
#include <stdio.h>

#define RAND_MAX 65536

static unsigned short rand_seed = 0;

/* srand:
 *  Seed initialization routine for rand() replacement.
 */
EXPORT void srand(int seed)
{
   rand_seed = seed;
}

/* _rand:
 *  Simple rand() replacement with guaranteed randomness in the lower 16 bits.
 */
EXPORT int rand(void)
{
   rand_seed = (rand_seed + 1) * 1103515245 + 12345;
   return rand_seed;
}

EXPORT int pow(int a,int b)
{
    int rs=1;
    while(b--)
        rs=rs*a;
    return rs;
}