How to take one particular number or a range of particular number from a set of number?

I am looking for to take one particular number or range of numbers from a set of number?

Example

A = [-10,-2,-3,-8, 0 ,1, 2, 3, 4 ,5,7, 8, 9, 10, -100];

• How can I just take number 5 from the set of above number and
• How can I take a range of number for example from -3 to 4 from A开发者_C百科.

Please help. Thanks

I don't know what you are trying to accomplish by this. But you could check each entry of the set and test it it's in the specified range of numbers. The test for a single number could be accomplished by testing each number explicitly or as a special case of range check where the lower and the upper bound are the same number.

looping and testing, no matter what the programming language is, although most programming languages have builtin methods for accomplishing this type of task (so you may want to specify what language are you supposed to use for your homework):

procfun get_element:
    index=0
    for element in set:
        if element is 5 then return (element,index)
        increment index

your "5" is in element and at set[index]

getting a range:

procfun getrange:    
    subset = []
    index = 0
    for element in set:
        if element is -3:
            push element in subset
            while index < length(set)-1:
                push set[index] in subset
                if set[index] is 4:
                    return subset
                increment index
            #if we met "-3" but we didn't met "4" then there's no such range
            return None
        #keep searching for a "-3"
        increment index
    return None

if ran against A, subset would be [-3,-8, 0 ,1, 2, 3, 4]; this is a "first matched, first grabbed" poorman's algorithm. on sorted sets the algorithms can get smarter and faster.