C how to generate a random number

CodePudding user response:

And the rand function srand function

CodePudding user response:

Fyi:

 # include & lt; stdio.h> 
#include  
#include  
Unsigned long ulrand (void) {
Return (
(((unsigned long) rand () & lt; <24) & amp; 0 xff000000ul) 
| (((unsigned long) rand () & lt; <12) & amp; 0 x00fff000ul) 
| (((unsigned long) rand ()) & amp; 0 x00000ffful)); 
} 
Unsigned __int64 ullrand (void) {
Return (
(((unsigned __int64) ulrand ()) & lt; <32) 
| ((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 (" % 010 lu 0 8 x x % \ n ", ul, ul); 
} 
for (i=0; i<10; I++) {
Ull=ullrand (); 
Printf (" % 020 i64u 0 x % 016 i64x \ n ", ull, ull); 
} 
} 
//3971076432 0 xecb1d150 
//2433428051 0 x910b2a53 
//1415415336 0 x545d8628 
//1312330759 0 x4e389407 
//1845758378 0 x6e0409aa 
//0008069933 0 x007b232d 
//4202720757 0 xfa806df5 
//2669855255 0 x9f22c217 
//0312068736 0 x1299ca80 
//2084555989 0 x7c3fccd5 
//03502077880857307931 0 x3099e1472040ab1b 
//16884702393146816355 0 xea52835e19b43763 
//01877364819396611730 0 x1a0dbd5b45f34e92 
//07839440151924835771 0 x6ccb4948756a05bb 
//09471412086917299176 0 x8371371c820bfbe8 
//04411255971577469925 0 x3d37edef2f321be5 
//13735846279546091130 0 xbe9f876a65b7367a 
//04512980766520059820 0 x3ea15418aa9927ac 
//15821377118299441610 0 xdb90d2a9f1bb49ca 
//15512417228822200185 0 xd7472d480398bf79