[35aab3] | 1 | /**************************************** |
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| 2 | * Computer Algebra System SINGULAR * |
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| 3 | ****************************************/ |
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| 4 | /*************************************************************** |
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| 5 | * File: p_Mult_q.cc |
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| 6 | * Purpose: multiplication of polynomials |
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| 7 | * Author: obachman (Olaf Bachmann) |
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| 8 | * Created: 8/00 |
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[a5cc448] | 9 | * Version: $Id: p_Mult_q.cc,v 1.9 2009-01-07 17:07:04 Singular Exp $ |
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[35aab3] | 10 | *******************************************************************/ |
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| 11 | #include "mod2.h" |
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| 12 | |
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| 13 | /*************************************************************** |
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| 14 | * |
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| 15 | * Returns: p * q, |
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| 16 | * Destroys: if !copy then p, q |
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| 17 | * Assumes: pLength(p) >= 2 pLength(q) >=2 |
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| 18 | ***************************************************************/ |
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| 19 | #include "p_polys.h" |
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| 20 | #include "p_Procs.h" |
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| 21 | #include "p_Numbers.h" |
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| 22 | #include "kbuckets.h" |
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| 23 | |
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| 24 | #include "p_Mult_q.h" |
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| 25 | |
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| 26 | BOOLEAN pqLength(poly p, poly q, int &lp, int &lq, const int min) |
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| 27 | { |
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| 28 | int l = 0; |
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| 29 | |
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| 30 | do |
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| 31 | { |
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| 32 | if (p == NULL) |
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| 33 | { |
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| 34 | lp = l; |
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| 35 | if (l < min) |
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| 36 | { |
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| 37 | if (q != NULL) |
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| 38 | lq = l+1; |
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| 39 | else |
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| 40 | lq = l; |
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| 41 | return FALSE; |
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| 42 | } |
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| 43 | lq = l + pLength(q); |
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| 44 | return TRUE; |
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| 45 | } |
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| 46 | pIter(p); |
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| 47 | if (q == NULL) |
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| 48 | { |
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| 49 | lq = l; |
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| 50 | if (l < min) |
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| 51 | { |
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| 52 | lp = l+1; |
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| 53 | return FALSE; |
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| 54 | } |
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| 55 | lp = l + 1 + pLength(p); |
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| 56 | return TRUE; |
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| 57 | } |
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| 58 | pIter(q); |
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| 59 | l++; |
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| 60 | } |
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| 61 | while (1); |
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| 62 | } |
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| 63 | |
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| 64 | |
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| 65 | static poly _p_Mult_q_Bucket(poly p, const int lp, |
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| 66 | poly q, const int lq, |
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| 67 | const int copy, const ring r) |
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| 68 | { |
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| 69 | assume(p != NULL && pNext(p) != NULL && q != NULL && pNext(q) != NULL); |
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| 70 | pAssume1(! pHaveCommonMonoms(p, q)); |
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[093f30e] | 71 | #ifdef HAVE_RINGS |
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[a5cc448] | 72 | assume(!rField_is_Ring(currRing)); |
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[093f30e] | 73 | #endif |
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[35aab3] | 74 | assume(lp >= 1 && lq >= 1); |
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| 75 | p_Test(p, r); |
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| 76 | p_Test(q, r); |
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| 77 | |
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| 78 | poly res = pp_Mult_mm(p,q,r); // holds initially q1*p |
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| 79 | poly qq = pNext(q); // we iter of this |
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| 80 | poly qn = pp_Mult_mm(qq, p,r); // holds p1*qi |
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| 81 | poly pp = pNext(p); // used for Lm(qq)*pp |
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| 82 | poly rr = res; // last monom which is surely not NULL |
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| 83 | poly rn = pNext(res); // pNext(rr) |
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| 84 | number n, n1; |
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| 85 | |
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| 86 | kBucket_pt bucket = kBucketCreate(r); |
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| 87 | |
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| 88 | // initialize bucket |
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| 89 | kBucketInit(bucket, pNext(rn), lp - 2); |
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| 90 | pNext(rn) = NULL; |
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| 91 | |
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| 92 | // now the main loop |
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| 93 | Top: |
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| 94 | if (rn == NULL) goto Smaller; |
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| 95 | p_LmCmpAction(rn, qn, r, goto Equal, goto Greater, goto Smaller); |
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| 96 | |
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| 97 | Greater: |
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| 98 | // rn > qn, so iter |
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| 99 | rr = rn; |
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| 100 | pNext(rn) = kBucketExtractLm(bucket); |
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| 101 | pIter(rn); |
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| 102 | goto Top; |
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| 103 | |
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| 104 | // rn < qn, append qn to rr, and compute next Lm(qq)*pp |
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| 105 | Smaller: |
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| 106 | pNext(rr) = qn; |
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| 107 | rr = qn; |
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| 108 | pIter(qn); |
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| 109 | Work: // compute res + Lm(qq)*pp |
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| 110 | if (rn == NULL) |
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| 111 | { |
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| 112 | pNext(rr) = pp_Mult_mm(pp, qq, r); |
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| 113 | kBucketInit(bucket, pNext(pNext(rr)), lp - 2); |
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| 114 | pNext(pNext(rr)) = NULL; |
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| 115 | } |
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| 116 | else |
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| 117 | { |
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| 118 | kBucketSetLm(bucket, rn); |
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| 119 | kBucket_Plus_mm_Mult_pp(bucket, qq, pp, lp - 1); |
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| 120 | pNext(rr) = kBucketExtractLm(bucket); |
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| 121 | } |
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| 122 | |
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| 123 | pIter(qq); |
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| 124 | if (qq == NULL) goto Finish; |
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| 125 | rn = pNext(rr); |
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| 126 | goto Top; |
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| 127 | |
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| 128 | Equal: |
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| 129 | n1 = pGetCoeff(rn); |
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| 130 | n = n_Add(n1, pGetCoeff(qn), r); |
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| 131 | n_Delete(&n1, r); |
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| 132 | if (n_IsZero(n, r)) |
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| 133 | { |
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| 134 | n_Delete(&n, r); |
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| 135 | p_LmFree(rn, r); |
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| 136 | } |
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| 137 | else |
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| 138 | { |
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| 139 | pSetCoeff0(rn, n); |
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| 140 | rr = rn; |
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| 141 | } |
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| 142 | rn = kBucketExtractLm(bucket); |
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| 143 | n_Delete(&pGetCoeff(qn),r); |
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| 144 | qn = p_LmFreeAndNext(qn, r); |
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| 145 | goto Work; |
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| 146 | |
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| 147 | Finish: |
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| 148 | assume(rr != NULL && pNext(rr) != NULL); |
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| 149 | pNext(pNext(rr)) = kBucketClear(bucket); |
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| 150 | kBucketDestroy(&bucket); |
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| 151 | |
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| 152 | if (!copy) |
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| 153 | { |
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| 154 | p_Delete(&p, r); |
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| 155 | p_Delete(&q, r); |
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| 156 | } |
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| 157 | p_Test(res, r); |
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| 158 | return res; |
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| 159 | } |
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| 160 | |
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[009d80] | 161 | #ifdef HAVE_RINGS |
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| 162 | static poly _p_Mult_q_Normal_ZeroDiv(poly p, poly q, const int copy, const ring r) |
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[35aab3] | 163 | { |
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| 164 | assume(p != NULL && pNext(p) != NULL && q != NULL && pNext(q) != NULL); |
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| 165 | pAssume1(! pHaveCommonMonoms(p, q)); |
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| 166 | p_Test(p, r); |
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| 167 | p_Test(q, r); |
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| 168 | |
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| 169 | poly res = pp_Mult_mm(p,q,r); // holds initially q1*p |
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[009d80] | 170 | poly qq = pNext(q); // we iter of this |
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| 171 | |
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| 172 | while (qq != NULL) |
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| 173 | { |
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| 174 | res = p_Plus_mm_Mult_qq(res, qq, p, r); |
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| 175 | pIter(qq); |
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| 176 | } |
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| 177 | |
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| 178 | if (!copy) |
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| 179 | { |
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| 180 | p_Delete(&p, r); |
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| 181 | p_Delete(&q, r); |
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[cea6f3] | 182 | } |
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[009d80] | 183 | |
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| 184 | p_Test(res, r); |
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| 185 | |
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| 186 | return res; |
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| 187 | } |
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| 188 | #endif |
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| 189 | |
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| 190 | static poly _p_Mult_q_Normal(poly p, poly q, const int copy, const ring r) |
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| 191 | { |
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| 192 | assume(p != NULL && pNext(p) != NULL && q != NULL && pNext(q) != NULL); |
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| 193 | #ifdef HAVE_RINGS |
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[2f959e8] | 194 | assume(rField_is_Domain(r)); |
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[cea6f3] | 195 | #endif |
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[009d80] | 196 | pAssume1(! pHaveCommonMonoms(p, q)); |
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| 197 | p_Test(p, r); |
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| 198 | p_Test(q, r); |
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| 199 | |
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| 200 | poly res = pp_Mult_mm(p,q,r); // holds initially q1*p |
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[35aab3] | 201 | poly qq = pNext(q); // we iter of this |
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| 202 | poly qn = pp_Mult_mm(qq, p,r); // holds p1*qi |
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| 203 | poly pp = pNext(p); // used for Lm(qq)*pp |
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| 204 | poly rr = res; // last monom which is surely not NULL |
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| 205 | poly rn = pNext(res); // pNext(rr) |
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| 206 | number n, n1; |
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| 207 | |
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| 208 | // now the main loop |
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| 209 | Top: |
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| 210 | if (rn == NULL) goto Smaller; |
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| 211 | p_LmCmpAction(rn, qn, r, goto Equal, goto Greater, goto Smaller); |
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| 212 | |
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| 213 | Greater: |
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| 214 | // rn > qn, so iter |
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| 215 | rr = rn; |
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| 216 | pIter(rn); |
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| 217 | goto Top; |
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| 218 | |
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| 219 | // rn < qn, append qn to rr, and compute next Lm(qq)*pp |
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| 220 | Smaller: |
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| 221 | pNext(rr) = qn; |
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| 222 | rr = qn; |
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| 223 | pIter(qn); |
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[cea6f3] | 224 | |
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[35aab3] | 225 | Work: // compute res + Lm(qq)*pp |
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| 226 | if (rn == NULL) |
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| 227 | pNext(rr) = pp_Mult_mm(pp, qq, r); |
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| 228 | else |
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| 229 | { |
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| 230 | pNext(rr) = p_Plus_mm_Mult_qq(rn, qq, pp, r); |
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| 231 | } |
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| 232 | |
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| 233 | pIter(qq); |
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| 234 | if (qq == NULL) goto Finish; |
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| 235 | rn = pNext(rr); |
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| 236 | goto Top; |
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| 237 | |
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| 238 | Equal: |
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| 239 | n1 = pGetCoeff(rn); |
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| 240 | n = n_Add(n1, pGetCoeff(qn), r); |
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| 241 | n_Delete(&n1, r); |
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| 242 | if (n_IsZero(n, r)) |
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| 243 | { |
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| 244 | n_Delete(&n, r); |
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| 245 | rn = p_LmFreeAndNext(rn, r); |
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| 246 | } |
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| 247 | else |
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| 248 | { |
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| 249 | pSetCoeff0(rn, n); |
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| 250 | rr = rn; |
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| 251 | pIter(rn); |
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| 252 | } |
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| 253 | n_Delete(&pGetCoeff(qn),r); |
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| 254 | qn = p_LmFreeAndNext(qn, r); |
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| 255 | goto Work; |
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| 256 | |
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| 257 | Finish: |
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| 258 | if (!copy) |
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| 259 | { |
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| 260 | p_Delete(&p, r); |
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| 261 | p_Delete(&q, r); |
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| 262 | } |
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| 263 | p_Test(res, r); |
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| 264 | return res; |
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| 265 | } |
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| 266 | |
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| 267 | |
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| 268 | poly _p_Mult_q(poly p, poly q, const int copy, const ring r) |
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| 269 | { |
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[93ebe1] | 270 | #ifdef HAVE_RINGS |
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| 271 | if (!rField_is_Domain(currRing)) |
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| 272 | return _p_Mult_q_Normal_ZeroDiv(p, q, copy, r); |
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| 273 | #endif |
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[35aab3] | 274 | int lp, lq, l; |
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| 275 | poly pt; |
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| 276 | |
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| 277 | pqLength(p, q, lp, lq, MIN_LENGTH_BUCKET); |
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| 278 | |
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| 279 | if (lp < lq) |
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| 280 | { |
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| 281 | pt = p; |
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| 282 | p = q; |
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| 283 | q = pt; |
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| 284 | l = lp; |
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| 285 | lp = lq; |
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| 286 | lq = l; |
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| 287 | } |
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| 288 | if (lq < MIN_LENGTH_BUCKET || TEST_OPT_NOT_BUCKETS) |
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| 289 | return _p_Mult_q_Normal(p, q, copy, r); |
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| 290 | else |
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| 291 | { |
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| 292 | assume(lp == pLength(p)); |
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| 293 | assume(lq == pLength(q)); |
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| 294 | return _p_Mult_q_Bucket(p, lp, q, lq, copy, r); |
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| 295 | } |
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| 296 | } |
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