| 1 | # Add rational numbers
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| 2 | #
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| 3 | # Input: tos-2 addend
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| 4 | #
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| 5 | # tos-1 addend
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| 6 | #
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| 7 | # Output: sum on stack
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| 8 |
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| 9 |
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| 10 |
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| 11 | qadd = ->
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| 12 | # a, ab, b, ba, c are all bigNum
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| 13 |
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| 14 | save()
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| 15 |
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| 16 | p2 = pop()
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| 17 | p1 = pop()
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| 18 |
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| 19 | ab = mmul(p1.q.a, p2.q.b)
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| 20 | ba = mmul(p1.q.b, p2.q.a)
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| 21 |
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| 22 | a = madd(ab, ba)
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| 23 |
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| 24 | #mfree(ab)
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| 25 | #mfree(ba)
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| 26 |
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| 27 | # zero?
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| 28 |
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| 29 | if (MZERO(a))
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| 30 | #mfree(a)
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| 31 | push(zero)
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| 32 | restore()
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| 33 | return
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| 34 |
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| 35 | b = mmul(p1.q.b, p2.q.b)
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| 36 |
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| 37 | c = mgcd(a, b)
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| 38 |
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| 39 | c = makeSignSameAs(c,b)
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| 40 |
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| 41 | p1 = new U()
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| 42 |
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| 43 | p1.k = NUM
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| 44 |
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| 45 | p1.q.a = mdiv(a, c)
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| 46 | p1.q.b = mdiv(b, c)
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| 47 |
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| 48 | #mfree(a)
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| 49 | #mfree(b)
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| 50 | #mfree(c)
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| 51 |
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| 52 | push(p1)
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| 53 |
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| 54 | restore()
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