ref: 4ba285fb7dc477013ce1fca68adf59244fc42bd4
dir: /sys/src/ape/lib/v/rand.c/
#define _RESEARCH_SOURCE #include <stdlib.h> #include <libv.h> /* random number generator from cacm 31 10, oct 88 for 32 bit integers (called long here) */ #ifdef MAIN #define A 16807 #define M 2147483647 #define Q 127773 #define R 2836 #else #define A 48271 #define M 2147483647 #define Q 44488 #define R 3399 #endif static long seed = 1; void srand(unsigned int newseed) { seed = newseed; } long lrand(void) { long lo, hi, test; hi = seed/Q; lo = seed%Q; test = A*lo - R*hi; if(test > 0) seed = test; else seed = test+M; return(seed); } int rand(void) { return lrand()%(RAND_MAX+1); } #ifdef MAIN main() { int i; for(i = 0; i < 10000; i++) rand(); if(seed == 1043618065) printf(" rand: pass\n"); else printf("*****rand: fail; seed=%u, should be 1043618065\n", seed); exit(0); } #endif