java - Data Structure for easy look up -

I am looking for data structure / algorithm in Java that does the following -

2. If there is no exact match in existence, then select the nearest (one value for B)
3. If the middle is fine, choose the higher - for example - my Pass numbers are
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I only know the value of A and by applying the above rules, make a straightforward look, Appropriate would / remove.

Example - 1

If I get 80 as value, then output is 0

Example - 2

If I If value is available as 75, then output 1 [according to rule 2]

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example - 3

If I get value as 70, then output 1 [rule] 3]

Any advice?

Updates based on comments - log (n) lookup is acceptable. I am open to implementing myself but need suggestions on how to achieve it. A range ranges from 0 to 1000 with accurate digits of 1 digit.

In fact there is already a data structure that is actually looking for you, which is .

There are ways in which you allow a 'key' to get 'floor' and 'roof'. After this, a little math will give you the value you really want to return:

  Public Fixed TreeMap & lt; Integer, Integer & gt; TM = new tree mark & ​​lt; & Gt; (); Public static zero principal (string [] args) Exception {throws tm.put (80, 0); Tm.put (76, 1); Tm.put (64, 3); Tm.put (56, 4); TM.Product (48, 10); Println (myGet (80)); // System.out.println (myGet (75)); // 1 System.out.println (myGet (70)); // 1} public static int myGet (int key) {integer value = tm.get (key); If (value == zero) {entry  

Note: I did not bother with the appropriate null when there is no floor / roof, but you get this idea.