题解 | #牛牛的三元组问题#

using System;
using System.Collections.Generic;


class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param nums int整型一维数组
     * @return int整型二维数组
     */
    public List<List<int>> findTriplets (List<int> nums) {
        nums.Sort();
        int count = nums.Count;

        List<List<int>> outputList = new List<List<int>>();
        for (int i = 0; i < count - 2; i++) {
            for (int j = i + 1; j < count - 1; j++) {
                for (int k = j + 1; k < count; k++) {
                    if ((nums[i] + nums[j] + nums[k]) == 0 ) {
                        List<int> output = new List<int>();
                        output.Add(nums[i]);
                        output.Add(nums[j]);
                        output.Add(nums[k]);
                        if (outputList.Find(l => l[0] == nums[i] && l[1] == nums[j] &&
                                            l[2] == nums[k]) == null)
                            outputList.Add(output);
                    }
                }
            }
        }

        return outputList;
    }
}