Question

所以我一直在尝试计算Bezout系数。我见过的所有解决方案都可以同时计算GCD。我已经有解决方法了。

所以这是我尝试过的代码的不同部分。

computeCoeffs :: Int -> Int -> (Int, Int)
computeCoeffs :: Int -> Int -> (Int, Int)
computeCoeffs a b =
  let bq = a - r; (q, r) = a `quotRem` b 
           in if b == 0 
              then (1, 0)
              else ((v, (u - q * v)) = computeCoeffs (a, b))
                    where a * v + b * (u - q * v) = gcd (a, b)

或代替最后一行

 let (q, r) = a `quotRem` b
 let r = a - bq
 | b == 0 = (1, 0)
 | otherwise (v, (u-qv)) = computeCoeffs (a, b)
     where a * v + b(u - q * v) = gcd (a, b)

我尝试过切换位置，删除或添加防护装置，但仍然会引发错误。

Answer 1

类似的东西应该起作用，需要处理“零除”错误的边缘情况

computeCoeff a b = go a b 1 0 0 1
     where go a b s0 s1 t0 t1 | r==0 = (s1,t1)
                              | otherwise = go b r s1 s t1 t
                              where (q,r) = quotRem a b
                                    (s,t) = (s0-s1*q, t0-t1*q)

> computeCoeff 240 46
(-9,47)

参考：Extended Euclidean algorithm

计算Haskell中的bezout系数

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