windows 下的随机数太扯淡了
stdlib.h
/* Maximum value that can be returned by the rand function. */
#define RAND_MAX 0x7fff //才3万多点
看看linux的
/* The largest number rand will return (same as INT_MAX). */
#define RAND_MAX 2147483647
这才靠谱啊
[解决办法]
32位
Window下的RAND_MAX为：0x7fff=2^15-1
Linxu下的RAND_MAX为 ：2^31-1
[解决办法]
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
unsigned long ulrand(void) {
return (
(((unsigned long)rand()<<24)&0xFF000000ul)
[解决办法]
(((unsigned long)rand()<<12)&0x00FFF000ul)
[解决办法]
(((unsigned long)rand() )&0x00000FFFul));
}
unsigned __int64 ullrand(void) {
return (
(((unsigned __int64)ulrand())<<32)
[解决办法]
((unsigned __int64)ulrand()));
}
int i;
unsigned long ul;
unsigned __int64 ull;
void main() {
srand(time(NULL));
for (i=0;i<10;i++) {
ul=ulrand();
printf("%010lu 0x%08x\n",ul,ul);
}
for (i=0;i<10;i++) {
ull=ullrand();
printf("%020I64u 0x%016I64x\n",ull,ull);
}
}
//3971076432 0xecb1d150
//2433428051 0x910b2a53
//1415415336 0x545d8628
//1312330759 0x4e389407
//1845758378 0x6e0409aa
//0008069933 0x007b232d
//4202720757 0xfa806df5
//2669855255 0x9f22c217
//0312068736 0x1299ca80
//2084555989 0x7c3fccd5
//03502077880857307931 0x3099e1472040ab1b
//16884702393146816355 0xea52835e19b43763
//01877364819396611730 0x1a0dbd5b45f34e92
//07839440151924835771 0x6ccb4948756a05bb
//09471412086917299176 0x8371371c820bfbe8
//04411255971577469925 0x3d37edef2f321be5
//13735846279546091130 0xbe9f876a65b7367a
//04512980766520059820 0x3ea15418aa9927ac
//15821377118299441610 0xdb90d2a9f1bb49ca
//15512417228822200185 0xd7472d480398bf79
