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/****************************************************************
* *
* Copyright (c) 2001-2023 Fidelity National Information *
* Services, Inc. and/or its subsidiaries. All rights reserved. *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#include "mdef.h"
#include "gtm_string.h"
#include "gtm_stdio.h"
#include "gtm_time.h"
#include "gtm_stdlib.h"
#include "random.h"
#define MAXNUM 2147483561L
#define MAX_RND_IDX 99
#define MAX_SEED_LEN 85
/* "global" random table -- must be visible to get_rand_from_table and
init_rand_table */
static int rannum_table[MAX_RND_IDX+1];
int get_rand_from_table (void)
{
int ini_index = rannum_table[MAX_RND_IDX - 1]%MAX_RND_IDX;
int fin_index = rannum_table[MAX_RND_IDX]%MAX_RND_IDX;
int temp_val1, temp_val2;
if ((temp_val2 = rannum_table[ini_index] - rannum_table[fin_index]) < 0) temp_val2 += 1000000000;
rannum_table[ini_index] = temp_val2;
rannum_table[MAX_RND_IDX - 1]--;
rannum_table[MAX_RND_IDX]--;
if (rannum_table[MAX_RND_IDX - 1] == 0) rannum_table[MAX_RND_IDX - 1] = 55;
if (rannum_table[MAX_RND_IDX] == 0) rannum_table[MAX_RND_IDX] = 55;
temp_val1 = rannum_table[MAX_RND_IDX]%42 + 56;
rannum_table[MAX_RND_IDX] = rannum_table[temp_val1];
rannum_table[temp_val1] = temp_val2;
return(rannum_table[MAX_RND_IDX]);
}
int init_rand_table (void)
{
char buf[MAX_RND_IDX+2];
char c_seed[MAX_SEED_LEN + 1];
int i_seed, seed_len;
int i, j, k;
time_t now;
now = time(NULL);
i_seed = (int) now;
if ((9999999999 < now) || (999999999 >= now)) /* punt: system clock is broken, or this code still in use after 20 Nov 2286 */
{
i_seed = (int) 1693256989; /* Set arbitrary 10 digit number */
}
SNPRINTF(c_seed, MAX_SEED_LEN + 1, "%d", i_seed);
seed_len = 10; /* strlen(c_seed) always 10 */
SNPRINTF(buf, MAX_RND_IDX + 2, "%s aEbFcGdHeI", c_seed);
for (i = 1; i < MAX_RND_IDX; i++)
rannum_table[i] = buf[i%seed_len] * 8171717 + i * 997;
i = 97; j = 12;
for (k = 1; k < MAX_RND_IDX; k++)
{
rannum_table[i] -= rannum_table[j];
if (rannum_table[i] < 0)
rannum_table[i] = -rannum_table[i];
i--; j--;
if (i == 0)
i=97;
if (j == 0)
j=97;
}
rannum_table[MAX_RND_IDX - 2] = 55;
rannum_table[MAX_RND_IDX - 1] = 24;
rannum_table[MAX_RND_IDX] = 77;
return 1; /* No error. This is added to make compiler happy */
}
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