[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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[341696] | 9 | * Version: $Id$ |
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[35aab3] | 10 | *******************************************************************/ |
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[599326] | 11 | #include <kernel/mod2.h> |
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[35aab3] | 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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[599326] | 19 | #include <kernel/options.h> |
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| 20 | #include <kernel/p_polys.h> |
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| 21 | #include <kernel/p_Procs.h> |
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| 22 | #include <kernel/p_Numbers.h> |
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| 23 | #include <kernel/kbuckets.h> |
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[35aab3] | 24 | |
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[599326] | 25 | #include <kernel/p_Mult_q.h> |
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[35aab3] | 26 | |
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| 27 | BOOLEAN pqLength(poly p, poly q, int &lp, int &lq, const int min) |
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| 28 | { |
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| 29 | int l = 0; |
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| 30 | |
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| 31 | do |
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| 32 | { |
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| 33 | if (p == NULL) |
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| 34 | { |
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| 35 | lp = l; |
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| 36 | if (l < min) |
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| 37 | { |
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| 38 | if (q != NULL) |
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| 39 | lq = l+1; |
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| 40 | else |
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| 41 | lq = l; |
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| 42 | return FALSE; |
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| 43 | } |
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| 44 | lq = l + pLength(q); |
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| 45 | return TRUE; |
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| 46 | } |
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| 47 | pIter(p); |
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| 48 | if (q == NULL) |
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| 49 | { |
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| 50 | lq = l; |
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| 51 | if (l < min) |
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| 52 | { |
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| 53 | lp = l+1; |
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| 54 | return FALSE; |
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| 55 | } |
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| 56 | lp = l + 1 + pLength(p); |
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| 57 | return TRUE; |
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| 58 | } |
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| 59 | pIter(q); |
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| 60 | l++; |
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| 61 | } |
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| 62 | while (1); |
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| 63 | } |
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| 64 | |
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| 65 | |
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| 66 | static poly _p_Mult_q_Bucket(poly p, const int lp, |
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| 67 | poly q, const int lq, |
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| 68 | const int copy, const ring r) |
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| 69 | { |
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| 70 | assume(p != NULL && pNext(p) != NULL && q != NULL && pNext(q) != NULL); |
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| 71 | pAssume1(! pHaveCommonMonoms(p, q)); |
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[093f30e] | 72 | #ifdef HAVE_RINGS |
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[a5cc448] | 73 | assume(!rField_is_Ring(currRing)); |
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[093f30e] | 74 | #endif |
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[35aab3] | 75 | assume(lp >= 1 && lq >= 1); |
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| 76 | p_Test(p, r); |
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| 77 | p_Test(q, r); |
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| 78 | |
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| 79 | poly res = pp_Mult_mm(p,q,r); // holds initially q1*p |
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| 80 | poly qq = pNext(q); // we iter of this |
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| 81 | poly qn = pp_Mult_mm(qq, p,r); // holds p1*qi |
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| 82 | poly pp = pNext(p); // used for Lm(qq)*pp |
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| 83 | poly rr = res; // last monom which is surely not NULL |
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| 84 | poly rn = pNext(res); // pNext(rr) |
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| 85 | number n, n1; |
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| 86 | |
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| 87 | kBucket_pt bucket = kBucketCreate(r); |
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| 88 | |
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| 89 | // initialize bucket |
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| 90 | kBucketInit(bucket, pNext(rn), lp - 2); |
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| 91 | pNext(rn) = NULL; |
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| 92 | |
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| 93 | // now the main loop |
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| 94 | Top: |
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| 95 | if (rn == NULL) goto Smaller; |
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| 96 | p_LmCmpAction(rn, qn, r, goto Equal, goto Greater, goto Smaller); |
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| 97 | |
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| 98 | Greater: |
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| 99 | // rn > qn, so iter |
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| 100 | rr = rn; |
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| 101 | pNext(rn) = kBucketExtractLm(bucket); |
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| 102 | pIter(rn); |
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| 103 | goto Top; |
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| 104 | |
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| 105 | // rn < qn, append qn to rr, and compute next Lm(qq)*pp |
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| 106 | Smaller: |
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| 107 | pNext(rr) = qn; |
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| 108 | rr = qn; |
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| 109 | pIter(qn); |
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| 110 | Work: // compute res + Lm(qq)*pp |
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| 111 | if (rn == NULL) |
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| 112 | { |
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| 113 | pNext(rr) = pp_Mult_mm(pp, qq, r); |
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| 114 | kBucketInit(bucket, pNext(pNext(rr)), lp - 2); |
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| 115 | pNext(pNext(rr)) = NULL; |
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| 116 | } |
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| 117 | else |
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| 118 | { |
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| 119 | kBucketSetLm(bucket, rn); |
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| 120 | kBucket_Plus_mm_Mult_pp(bucket, qq, pp, lp - 1); |
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| 121 | pNext(rr) = kBucketExtractLm(bucket); |
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| 122 | } |
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| 123 | |
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| 124 | pIter(qq); |
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| 125 | if (qq == NULL) goto Finish; |
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| 126 | rn = pNext(rr); |
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| 127 | goto Top; |
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| 128 | |
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| 129 | Equal: |
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| 130 | n1 = pGetCoeff(rn); |
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| 131 | n = n_Add(n1, pGetCoeff(qn), r); |
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| 132 | n_Delete(&n1, r); |
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| 133 | if (n_IsZero(n, r)) |
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| 134 | { |
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| 135 | n_Delete(&n, r); |
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| 136 | p_LmFree(rn, r); |
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| 137 | } |
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| 138 | else |
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| 139 | { |
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| 140 | pSetCoeff0(rn, n); |
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| 141 | rr = rn; |
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| 142 | } |
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| 143 | rn = kBucketExtractLm(bucket); |
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| 144 | n_Delete(&pGetCoeff(qn),r); |
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| 145 | qn = p_LmFreeAndNext(qn, r); |
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| 146 | goto Work; |
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| 147 | |
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| 148 | Finish: |
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| 149 | assume(rr != NULL && pNext(rr) != NULL); |
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| 150 | pNext(pNext(rr)) = kBucketClear(bucket); |
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| 151 | kBucketDestroy(&bucket); |
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| 152 | |
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| 153 | if (!copy) |
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| 154 | { |
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| 155 | p_Delete(&p, r); |
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| 156 | p_Delete(&q, r); |
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| 157 | } |
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| 158 | p_Test(res, r); |
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| 159 | return res; |
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| 160 | } |
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| 161 | |
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[009d80] | 162 | #ifdef HAVE_RINGS |
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| 163 | static poly _p_Mult_q_Normal_ZeroDiv(poly p, poly q, const int copy, const ring r) |
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[35aab3] | 164 | { |
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| 165 | assume(p != NULL && pNext(p) != NULL && q != NULL && pNext(q) != NULL); |
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| 166 | pAssume1(! pHaveCommonMonoms(p, q)); |
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| 167 | p_Test(p, r); |
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| 168 | p_Test(q, r); |
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| 169 | |
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| 170 | poly res = pp_Mult_mm(p,q,r); // holds initially q1*p |
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[009d80] | 171 | poly qq = pNext(q); // we iter of this |
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| 172 | |
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| 173 | while (qq != NULL) |
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| 174 | { |
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| 175 | res = p_Plus_mm_Mult_qq(res, qq, p, r); |
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| 176 | pIter(qq); |
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| 177 | } |
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| 178 | |
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| 179 | if (!copy) |
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| 180 | { |
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| 181 | p_Delete(&p, r); |
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| 182 | p_Delete(&q, r); |
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[cea6f3] | 183 | } |
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[009d80] | 184 | |
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| 185 | p_Test(res, r); |
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| 186 | |
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| 187 | return res; |
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| 188 | } |
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| 189 | #endif |
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| 190 | |
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| 191 | static poly _p_Mult_q_Normal(poly p, poly q, const int copy, const ring r) |
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| 192 | { |
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| 193 | assume(p != NULL && pNext(p) != NULL && q != NULL && pNext(q) != NULL); |
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| 194 | #ifdef HAVE_RINGS |
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[2f959e8] | 195 | assume(rField_is_Domain(r)); |
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[cea6f3] | 196 | #endif |
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[009d80] | 197 | pAssume1(! pHaveCommonMonoms(p, q)); |
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| 198 | p_Test(p, r); |
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| 199 | p_Test(q, r); |
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| 200 | |
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| 201 | poly res = pp_Mult_mm(p,q,r); // holds initially q1*p |
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[35aab3] | 202 | poly qq = pNext(q); // we iter of this |
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| 203 | poly qn = pp_Mult_mm(qq, p,r); // holds p1*qi |
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| 204 | poly pp = pNext(p); // used for Lm(qq)*pp |
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| 205 | poly rr = res; // last monom which is surely not NULL |
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| 206 | poly rn = pNext(res); // pNext(rr) |
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| 207 | number n, n1; |
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| 208 | |
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| 209 | // now the main loop |
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| 210 | Top: |
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| 211 | if (rn == NULL) goto Smaller; |
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| 212 | p_LmCmpAction(rn, qn, r, goto Equal, goto Greater, goto Smaller); |
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| 213 | |
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| 214 | Greater: |
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| 215 | // rn > qn, so iter |
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| 216 | rr = rn; |
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| 217 | pIter(rn); |
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| 218 | goto Top; |
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| 219 | |
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| 220 | // rn < qn, append qn to rr, and compute next Lm(qq)*pp |
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| 221 | Smaller: |
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| 222 | pNext(rr) = qn; |
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| 223 | rr = qn; |
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| 224 | pIter(qn); |
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[cea6f3] | 225 | |
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[35aab3] | 226 | Work: // compute res + Lm(qq)*pp |
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| 227 | if (rn == NULL) |
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| 228 | pNext(rr) = pp_Mult_mm(pp, qq, r); |
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| 229 | else |
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| 230 | { |
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| 231 | pNext(rr) = p_Plus_mm_Mult_qq(rn, qq, pp, r); |
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| 232 | } |
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| 233 | |
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| 234 | pIter(qq); |
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| 235 | if (qq == NULL) goto Finish; |
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| 236 | rn = pNext(rr); |
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| 237 | goto Top; |
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| 238 | |
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| 239 | Equal: |
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| 240 | n1 = pGetCoeff(rn); |
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| 241 | n = n_Add(n1, pGetCoeff(qn), r); |
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| 242 | n_Delete(&n1, r); |
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| 243 | if (n_IsZero(n, r)) |
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| 244 | { |
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| 245 | n_Delete(&n, r); |
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| 246 | rn = p_LmFreeAndNext(rn, r); |
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| 247 | } |
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| 248 | else |
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| 249 | { |
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| 250 | pSetCoeff0(rn, n); |
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| 251 | rr = rn; |
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| 252 | pIter(rn); |
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| 253 | } |
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| 254 | n_Delete(&pGetCoeff(qn),r); |
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| 255 | qn = p_LmFreeAndNext(qn, r); |
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| 256 | goto Work; |
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| 257 | |
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| 258 | Finish: |
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| 259 | if (!copy) |
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| 260 | { |
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| 261 | p_Delete(&p, r); |
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| 262 | p_Delete(&q, r); |
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| 263 | } |
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| 264 | p_Test(res, r); |
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| 265 | return res; |
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| 266 | } |
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| 267 | |
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| 268 | |
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| 269 | poly _p_Mult_q(poly p, poly q, const int copy, const ring r) |
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| 270 | { |
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[93ebe1] | 271 | #ifdef HAVE_RINGS |
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| 272 | if (!rField_is_Domain(currRing)) |
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| 273 | return _p_Mult_q_Normal_ZeroDiv(p, q, copy, r); |
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| 274 | #endif |
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[35aab3] | 275 | int lp, lq, l; |
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| 276 | poly pt; |
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| 277 | |
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| 278 | pqLength(p, q, lp, lq, MIN_LENGTH_BUCKET); |
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| 279 | |
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| 280 | if (lp < lq) |
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| 281 | { |
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| 282 | pt = p; |
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| 283 | p = q; |
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| 284 | q = pt; |
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| 285 | l = lp; |
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| 286 | lp = lq; |
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| 287 | lq = l; |
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| 288 | } |
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| 289 | if (lq < MIN_LENGTH_BUCKET || TEST_OPT_NOT_BUCKETS) |
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| 290 | return _p_Mult_q_Normal(p, q, copy, r); |
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| 291 | else |
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| 292 | { |
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| 293 | assume(lp == pLength(p)); |
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| 294 | assume(lq == pLength(q)); |
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| 295 | return _p_Mult_q_Bucket(p, lp, q, lq, copy, r); |
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| 296 | } |
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| 297 | } |
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