efficient.py

f = open('input.txt')
lines = f.readlines()
lines = list(map(lambda x: int(x.strip()), lines))
f.close()

d = {}
found = {}

for line in lines:
    if line in d:
        d[line] += 1
    else:
        d[line] = 1

nums = list(d.keys())
nums.sort()

left = 0
right = len(nums) - 1
count = 0
num_range = (-10000, 10000)

while left < right:
    s = nums[left] + nums[right]
    if s >= num_range[0] and s <= num_range[1]:
        if s not in found:
            count += 1
            found[s] = True

        left += 1
        right -= 1
    elif s < num_range[0]:
        left += 1
    else:
        right -= 1

print(count)

naive.py

f = open('input.txt')
lines = f.readlines()
f.close()

d = {}

for i in lines:
    val = int(i.strip('\r\n'))

    if d.has_key(i):
        d[val] += 1
    else:
        d[val] = 1

res = 0

sorts = d.keys()
sorts.sort()

def sums(arr, target, d):
    size = len(arr)

    x = arr[:(size/2)]
    y = arr[(size/2):]

    the_arr = [] 

    if target >= x[0] or target <= x[len(x)-1]:
        the_arr = x
    elif target >= y[0] or target <= y[len(y)-1]:
        the_arr = y
    else:
        return False

    print total
    left = 0
    right = len(the_arr)-1
    
    for el in the_arr:
        if d.has_key(target-el):
            return True

    return False

for total in xrange(-10000,10001):
    print total
    if sums(sorts, total, d):
        res += 1

print "result: "+str(res)