561. array split

Original link: https://leetcode-cn.com/problems/array-partition-i/

 

topic:

Thinking Analysis: This question is given a length 2n array, then these will be divided into n number of pairs,

1. The array elements in ascending order.

2 through the array, the subscript of the array elements is accumulated even.

3. Finally, return the results accumulated.

Source:

class Solution {
    public int arrayPairSum(int[] nums) {
        //insertSort(nums);
        Arrays.sort(nums);
        int sum = 0;
        for(int i = 0;i < nums.length;i+=2){
            sum+=nums[i];
        }
        return sum;
    }
    public static int[] insertSort(int[] nums){
        int e;
        int j;
        for(int i = 1;i < nums.length;i++){
            e = nums[i];
            for(j = i;j > 0 && nums[j - 1] > e;j--){
                nums[j] = nums[j - 1];
            }
            nums[j] = e;
        }
        return nums;
    }
}