Find N Unique Integers Sum up to Zero

给一个数字n, 返回一个数组, 里面有n个数, 里面的数相加等于0. 这个就是观察一下奇偶规律.

class Solution {
    public int[] sumZero(int n) {
        int[] res = new int[n];
        if(n % 2 == 0){ // if even, n = 4  1 -1 2 -2
            int k = 0;
            for(int i = 1; i <= n/2; i++){
                res[k++] = i;
                res[k++] = -i;
            }
        }
        else {
            int k = 0;
            res[k] = 0;
            for(int i = 1; i <= n/2; i++){
                res[k++] = i;
                res[k++] = -i;
            }
        }
        return res;
    }
}