Any Python gurus here?

[Naez]

The following code does a sequential search of a string (phonebook).

 

def main()    #input
    inp = (raw_input('Input: '))

    #given string
    phonebook = 'bcdfghjklmnpqrstvwxyz'

    # counter variables.
    count = 0
    totalbad = 0
    totalgood = 0
    fails = 0
    success = 0
    
    for char in inp:
        found = 0
        compares = 1
        for char in phonebook:
            if char > inp[count]:
                break
            if char == inp[count]:
                found = 1
                break
            else:
                compares = compares + 1
        if found:
            print inp[count] + " found with " + str(compares) + " compares"
            totalgood += compares
            success += 1
        else:
            print inp[count] + " not found with " + str(compares) + " compares"
            totalbad += compares
            fails += 1
        count += 1

    if fails != 0:   
        failavg = 1.0 * totalbad / fails
    if success != 0:
        sucavg = 1.0 * totalgood / success 

    print "number success = " + str(success) + "; total compares = " + str(totalgood) + "; average = " + str(sucavg)
    print "number failures = " + str(fails) + "; total compares = " + str(totalbad) + "; average = " + str(failavg)
   
if __name__ == '__main__':
    main() 

 

 

I have to modify the code to do a binary search, starting from the middle of the string... for instance:

 

 

Given: phonebook = 'bfmrs'

Output:

search char 'm' - found compares 1

search char 'n' - not found compares 2

search char 'b' - found compares 3

search char 'c' not found compares 3

 

 

 

My deadline is tomorrow.  If anyone can help me figure this out I would greatly appreciate it.

[Naez]

Not the prettiest code, but I think I got it working

 

def main()
    #input
    inp = (raw_input('Input: '))

    #given string
    phonebook = 'bcdfghjklmnpqrstvwxyz'
    #phonebook = 'bfmrs'

    # counter variables.
    count = 0
    totalbad = 0
    totalgood = 0
    fails = 0
    success = 0

    mid = phonebook[len(phonebook)/2:]
    start = phonebook[:len(phonebook)/2]
    
    for char in inp:
        found = 0
        compares = 1
        middie = 0
        for char in mid:
            if char <= inp[count]:
                middie = 1
            else:
                break
            if char == inp[count]:
                found = 1
                break
            else:
                compares = compares + 1

        if (found == 0) & (middie == 0):
            compares = len(mid)
            for char in start:
                if char > inp[count]:
                    break
                if char == inp[count]:
                    found = 1
                    break
                else:
                    compares = compares +1
            
        if found:
            print inp[count] + " found with " + str(compares) + " compares"
            totalgood += compares
            success += 1
        else:
            print inp[count] + " not found with " + str(compares) + " compares"
            totalbad += compares
            fails += 1
        count += 1

    sucavg = 0.0
    failavg = 0.0
    if fails != 0:   
        failavg = 1.0 * totalbad / fails
    if success != 0:
        sucavg = 1.0 * totalgood / success 

    print "number success = " + str(success) + "; total compares = " + str(totalgood) + "; average = " + str(sucavg)
    print "number failures = " + str(fails) + "; total compares = " + str(totalbad) + "; average = " + str(failavg)

if __name__ == '__main__':
    main()