/**
 * @author Chaos
 * @version my solution
 * 561. Array Partition I
 * 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].
 *
 *
 * use integrated sort package, then get the sum of even number
 */

class Solution {
    public int arrayPairSum(int[] nums) {
        Arrays.sort(nums);
        int sum=0;
        for (int i=0; i<nums.length; i+=2){
            sum += nums[i];
        }
        return sum;
    }
}