Double Type equal judgment

When the computer determines that two numbers are equal, it will determine whether all binary bits are equal. When all bits are equal, the two numbers are equal, absolutely equal.

However, for decimal places, it is enough to retain the digits after the decimal point. Therefore, the difference between the two decimal places can be considered equal within the acceptable precision range.

/* A = B */intDequals(Double A, double B) {return FABS (a-B) <0.000001 ;}

In this case, when A> B, A may be equal to B. Therefore, when determining the size relationship, first judge whether a is equal to B.