アルゴリズム：Leetcode.15。3つの数値の合計

件名：https : //leetcode-cn.com/problems/3sum/

回答：ダブルポインタ

 public List <List <Integer >> threeSum（int [] nums）{

     Arrays.sort（nums）;

        int len = nums.length;

        List <List <Integer >> result = new ArrayList <>（）;

        for（int i = 0; i <len; i ++）{

            if（i> 0 && nums [i] == nums [i-1]）{

                継続する;

            }

            if（nums [i]> 0）ブレーク;

            int right = len-1;

            int target = -nums [i];

            for（int left = i + 1; left <len; left ++）{

                if（left> i + 1 && nums [left] == nums [left-1]）{

                    継続する;

                }

                if（nums [i] + nums [left]> 0）ブレーク;

                while（left <right && nums [left] + nums [right]> target）{

                    正しい - ;

                }

                if（left == right）break;

                if（nums [左] + nums [右] ==ターゲット）{

                    List <Integer> list = new ArrayList <>（）;

                    list.add（nums [i]）;

                    list.add（nums [left]）;

                    list.add（nums [right]）;

                    result.add（list）;

                }

            }

        }

        結果を返す;

    }