Description

O(n²)

#!/usr/bin/python
'''LeetCode question 1
'''

def twoSum(nums, target):
    n = len(nums);
    for i in xrange(n-1):
        for j in xrange(i+1, n):
            if (nums[i] + nums[j]) == target:
                return i, j

def main():
    nums = [2, 7, 11, 15]
    target = 9

    index = twoSum(nums, target)

    if index:
        print index
    else:
        print 'No pair has been found for target %d' % target

if __name__ == '__main__':
    main()
			

O(n)

#!/usr/bin/python
'''LeetCode question 1
'''

def twoSum(nums, target):
    d = {}
    for indx, ele in enumerate(nums):
        if d.has_key(target-ele):
            return (d[target-ele], indx)
        else:
            d[ele] = indx

def main():
    nums = [2, 7, 11, 15]
    target = 9

    index = twoSum(nums, target)

    if index:
        print index
    else:
        print 'No pair has been found for target %d' % target

if __name__ == '__main__':
    main()
			

#!/usr/bin/python
'''LeetCode question 1
'''

def twoSum(nums, target):
    d = {}
    for indx, ele in enumerate(nums):
        if d.has_key(ele):
            return d[ele], indx
        else:
            d[target-ele] = indx

def main():
    nums = [2, 7, 11, 15]
    target = 9

    index = twoSum(nums, target)

    if index:
        print index
    else:
        print 'No pair has been found for target %d' % target

if __name__ == '__main__':
    main()