随机函数rand()算法

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 
 4 
 5 #define _A 214013LL
 6 #define _B 2531011LL
 7 
 8 
 9 int a;
10 
11 
12 void mysrand(int x)
13 {
14     a = x;
15 }
16 
17 
18 int myrand()
19 {
20     return ((a = a * _A + _B)>>16) & 0x7fff;
21 }
22 
23 
24 int main()
25 {
26     mysrand(0);
27     srand(0);
28     while (1)
29     {
30         printf ("%d, %d\n", rand(), myrand());
31         getchar();
32     }
33     return 0;
34 }