#ifndef lint static char sccsid[] = "@(#)random.c 5.1 (Berkeley) 11/25/87"; #endif /* not lint */ static long rntb[32] = { 3, 0x9a319039, 0x32d9c024, 0x9b663182, 0x5da1f342, 0xde3b81e0, 0xdf0a6fb5, 0xf103bc02, 0x48f340fb, 0x7449e56b, 0xbeb1dbb0, 0xab5c5918, 0x946554fd, 0x8c2e680f, 0xeb3d799f, 0xb11ee0b7, 0x2d436b86, 0xda672e2a, 0x1588ca88, 0xe369735d, 0x904f35f7, 0xd7158fd6, 0x6fa6f051, 0x616e6b96, 0xac94efdc, 0x36413f93, 0xc622c298, 0xf5a42ab8, 0x8a88d77b, 0xf5ad9d0e, 0x8999220b, 0x27fb47b9 }; static long *fptr = &rntb[4]; static long *rptr = &rntb[1]; static long *state = &rntb[1]; static int rand_type = 3; static int rand_deg = 31; static int rand_sep = 3; static long *end_ptr = &rntb[32]; srrandom(x) int x; { register int i; long rrandom(); state[0] = (long) x; if (rand_type != 0) { for (i = 1; i < rand_deg; i++) { state[i] = 1103515245 * state[i - 1] + 12345; } fptr = &state[rand_sep]; rptr = &state[0]; for (i = 0; i < 10 * rand_deg; i++) { (void) rrandom(); } } } long rrandom() { long i; if (rand_type == 0) { i = state[0] = (state[0]*1103515245 + 12345) & 0x7fffffff; } else { *fptr += *rptr; i = (*fptr >> 1) & 0x7fffffff; if (++fptr >= end_ptr) { fptr = state; ++rptr; } else { if (++rptr >= end_ptr) { rptr = state; } } } return(i); } get_rand(x, y) register int x, y; { register int r, t; long lr; if (x > y) { t = y; y = x; x = t; } lr = rrandom(); lr &= (long) 0x00003fff; r = (int) lr; r = (r % ((y - x) + 1)) + x; return(r); } rand_percent(percentage) register int percentage; { return(get_rand(1, 100) <= percentage); } coin_toss() { return(((rrandom() & 01) ? 1 : 0)); }