#/***********************************************************
#    Math::sqrt.rb -- 平方根
#***********************************************************/

def mysqrt(x)  # 自家版 $\sqrtxend$ 
    if (x > 0) 
        if (x > 1); s = x; else; s = 1; end
        begin 
            last = s;  s = (x / s.to_f + s) / 2.0
        end while (s < last)
        return last
    end
    if (x != 0); $stderr.printf("mysqrt: domain error\n"); end
    return 0
end

def lsqrt(x)
    if (x == 0); return 0; end
    s = mysqrt(x)
    return (x / s.to_f + s) / 2.0
end

DBL_DIG = 15    # <float.h>
LDBL_DIG = 18

for i in 0..20
    printf("%2d  %.*f %.*f\n",\
        i, DBL_DIG - 1, mysqrt(i),\
        LDBL_DIG - 1, lsqrt(i))
end

exit 0