h.mex

来自「强大的数学工具包」· MEX 代码 · 共 43 行

                               * * * * * * *
                               *    mex    *
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        "modular exponentiation"
        SYNTAX: X = mex(M, A, N)

        M is an expression whose value is a positive integer.
        A is an expression whose value is an integer or a rational 
        number whose denominator is relatively prime to M.
        N is an expression whose value is an integer.

        X is assigned (A^N) mod M.

        "mex(M, A, N)" is much faster than (A^N) mod M.
        "mex(M, A, N)" is equivalent to "curmod(M) _ MOD(A)^N".


        Example 1: (correct)

                mex(17, 12, 100)


        Example 2: (incorrect)
                
                mex(3, x + 2, 4)
                        
_ERR_NR_055


        Example 3: (incorrect)

                mex(4/3, 3, 5)
                
_ERR_NR_222


        Example 4: (incorrect)

                mex(6, 456, -4/3)
                
_ERR_NR_054