108 lines
1.4 KiB
C++
108 lines
1.4 KiB
C++
// Convert bignum to string
|
|
|
|
#include "stdafx.h"
|
|
#include "defs.h"
|
|
|
|
static int divby1billion(unsigned int *);
|
|
|
|
static char *str;
|
|
static int len;
|
|
|
|
char *
|
|
mstr(unsigned int *a)
|
|
{
|
|
int k, n, r, sign;
|
|
char c;
|
|
|
|
if (str == NULL) {
|
|
str = (char *) malloc(1000);
|
|
len = 1000;
|
|
}
|
|
|
|
// estimate string size
|
|
|
|
n = 10 * MLENGTH(a) + 2;
|
|
|
|
if (n > len) {
|
|
free(str);
|
|
str = (char *) malloc(n);
|
|
len = n;
|
|
}
|
|
|
|
sign = MSIGN(a);
|
|
|
|
a = mcopy(a);
|
|
|
|
k = len - 1;
|
|
|
|
str[k] = 0;
|
|
|
|
for (;;) {
|
|
k -= 9;
|
|
r = divby1billion(a);
|
|
c = str[k + 9];
|
|
sprintf(str + k, "%09d", r);
|
|
str[k + 9] = c;
|
|
if (MZERO(a))
|
|
break;
|
|
}
|
|
|
|
// remove leading zeroes
|
|
|
|
while (str[k] == '0')
|
|
k++;
|
|
|
|
if (str[k] == 0)
|
|
k--;
|
|
|
|
// sign
|
|
|
|
if (sign == -1) {
|
|
k--;
|
|
str[k] = '-';
|
|
}
|
|
|
|
mfree(a);
|
|
|
|
return str + k;
|
|
}
|
|
|
|
// Returns remainder as function value, quotient returned in a.
|
|
|
|
static int
|
|
divby1billion(unsigned int *a)
|
|
{
|
|
int i;
|
|
unsigned long long kk;
|
|
|
|
kk = 0;
|
|
|
|
for (i = MLENGTH(a) - 1; i >= 0; i--) {
|
|
|
|
#ifndef MAC
|
|
((unsigned int *) &kk)[1] = ((unsigned int *) &kk)[0];
|
|
((unsigned int *) &kk)[0] = a[i];
|
|
#else
|
|
((unsigned int *) &kk)[0] = ((unsigned int *) &kk)[1];
|
|
((unsigned int *) &kk)[1] = a[i];
|
|
#endif
|
|
a[i] = (int) (kk / 1000000000);
|
|
|
|
kk -= (unsigned long long) 1000000000 * a[i];
|
|
}
|
|
|
|
// length of quotient
|
|
|
|
for (i = MLENGTH(a) - 1; i > 0; i--)
|
|
if (a[i])
|
|
break;
|
|
|
|
MLENGTH(a) = i + 1;
|
|
|
|
#ifndef MAC
|
|
return ((unsigned int *) &kk)[0];
|
|
#else
|
|
return ((unsigned int *) &kk)[1];
|
|
#endif
|
|
}
|