ArrayPartition1.py

'''
Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), ..., (an, bn) which makes sum of min(ai, bi) for all i from 1 to n as large as possible.

Example 1:
Input: [1,4,3,2]

Output: 4
Explanation: n is 2, and the maximum sum of pairs is 4 = min(1, 2) + min(3, 4).
Note:
n is a positive integer, which is in the range of [1, 10000].
All the integers in the array will be in the range of [-10000, 10000].


'''

class Solution(object):
    def arrayPairSum(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        nums.sort()
        sum = 0
        for x in range(0,len(nums),2):
            sum += nums[x]
        return sum

sol = Solution


'''
Complexity
O(nlogn)
O(1)



'''

'''
Things learnt 
While doing a for loop how to increment the counter by 2 or other number

for x in range(0,len(nums),2):
    print(x)

How to sort an array in place with out using extra space

if array is nums
then nums.sort()


'''