1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
/*======================================================================
FINDRATCOORD(S;t,R,P)
Find rational coordinate
Inputs:
S : a list (S_1,...,S_r), S_i a list of primitive irreducible
i-variate saclib pols
Outputs:
t : a BDigit
R : a rational number
P : SACLIB polynomial
If some element of some S_i is a x_i + b, a,b \in Z, then
t = i, R = -b/a and P = a x_i + b (as an element of Z[x_1,...,x_t]).
Otherwise t = 0.
======================================================================*/
#include "qepcad.h"
void FINDRATCOORD(Word S, Word* t_, Word *R_, Word *P_)
{
Word r, i, L, R;
r = LENGTH(S);
for(i = 1; i <= r; i++)
{
for(L = LELTI(S,i); L != NIL; L = RED(L))
{
R = IPRSOL(i,FIRST(L));
if (R != NIL)
{
*t_ = i;
*R_ = R;
*P_ = FIRST(L);
return;
}
}
}
*t_ = 0;
return;
}
|
