iven 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).
从优化上来说 只要尽可能的把小的聚集在一起，把大的聚集在一起就好了。
class Solution {
public int arrayPairSum(int[] nums) {
Arrays.sort(nums);
int result = 0 ;
for(int i = 0 ;i<nums.length;i+=2)
{
result+=nums[i];
}
return result ;
}
}
