随机数

 1 #define _CRT_SECURE_NO_WARNINGS//关闭安全检查
 2 # include<stdio.h>
 3 # include<stdlib.h>
 4 /*
 5     伪随机数的生成
 6 */
 7 int main1()
 8 {
 9     int seed = 0xffffffff,i;
10     srand((unsigned int)seed);//种子
11     for (i = 0; i < 5; i++)
12         printf("%d\t", rand() % 10);//生成0~9之间的数
13     printf("\n\n");
14     system("pause");
15 }
16 
17 /*
18     用时间生成随机数
19 */
20 
21 int main2()
22 {
23     time_t ts;
24     srand((unsigned int)time(&ts));
25     int num = rand()%100+1;
26     printf("%d", num);
27     getchar();
28 
29 }
30 
31 /*
32 生成的结果不在意料之中，记录一下
33 */
34 int main()
35 {
36     int seed, i;
37     for (;;)
38     {
39         printf("Please input a number to set the seed:");
40         scanf("%d", &seed);
41         if (seed == 0)
42             break;
43         srand((unsigned int)seed);
44         for (i = 0; i < 5; i++)
45             printf("%d\t", rand());
46         printf("\n\n");
47     }
48     system("pause");
49 }