随机数算法_C/C++

/*1.从同一个种子开始*/
#include <stdio.h>
#include <conio.h>
static unsigned long int next=1; int rand0(void)
{
next=next*1103515245+12345;
return (unsigned int)(next/65536)%32768;
} int main(void)
{
int count; for(count=0;count<5;count++)
printf("%hd\n",rand0());
getch();
return 0;
} /*2.重置种子*/
#include <stdio.h>
#include <conio.h>
static unsigned long int next=1; int rand1(void)
{
next=next*1103515245+12345;
return (unsigned int)(next/65536)%32768;
} void srand1(unsigned int seed)
{
next=seed;
} int main(void)
{
int count;
unsigned int seed; printf("please input seed:");
scanf("%u",&seed);
srand1(seed);
for(count=0;count<5;count++)
printf("%hd\n",rand1());
getch();
return 0;
} /*3.利用利用时钟产生种子
ANSI C程序库提供了rand()函数来产生随机数；
ANSI C程序库提供了srand()函数来产生种子；
ANSI C程序库提供了time()函数返回系统时间。
*/
#include <time.h>
#include <stdio.h>
#include <dos.h>
#include <conio.h>
#include <stdlib.h> int main(void) {
int i;
time_t t;
clrscr();
t = time(NULL);
srand((unsigned) t);
for(i=0; i<10; i++) printf("%d\n", rand()%10);
getch();
return 0;
}