Modulus in Java

问题

I want to get the value of an unknown number in equation containing modulus % in Java

For example:

x % 26 = y if I have the value of y how can I get x

回答1:

The problem is that there are either zero solutions (if Math.abs(y) >= 26) or an infinite¹ number of values of x that satisfy that equation for a given y. The general answer is:

x = 26 * k + y

for any integer value of k. You can pick whatever k you want.²

¹ In practice, the range will be limited by the range of integer values you are using. If x and y are int values, then you are limited by Integer.MAX_VALUE and Integer.MIN_VALUE. On the other hand, if they are BigInteger values, you don't have much in the way of range constraints.

² Actually, the signs of x and y must be the same in Java, so you only have half of infinity to pick from. :-)

回答2:

You can't get the value of x, that's how modulus works. You just know x = 26 * k + y where k is an integer.

来源：https://stackoverflow.com/questions/16237319/modulus-in-java