fig10_55.c

来自「数据结构与算法分析(C语言描述)的源代码 里面的代码的质量非常高」· C语言 代码 · 共 42 行

        /* Bad random number generator */

        #include <stdio.h>

/* START: fig10_55.txt */
        static unsigned long Seed = 1;

        #define A 48271L
        #define M 2147483647L
        #define Q ( M / A )
        #define R ( M % A )

        double
        Random( void )
        {
            long TmpSeed;

            TmpSeed = A * ( Seed % Q ) - R * ( Seed / Q );
            if( TmpSeed >= 0 )
                Seed = TmpSeed;
            else
                Seed = TmpSeed + M;

            return ( double ) Seed / M;
        }

        void
        Initialize( unsigned long InitVal )
        {
            Seed = InitVal;
        }
/* END */

main( )
{
    int i;

    for( i = 0; i < 20; i++ )
        printf( "%6f\n", Random( ) );
    return 0;
}