最接近的三数之和(leetcode16)

public class leetcode16 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Scanner in = new Scanner(System.in);
        String input = in.nextLine();
        List<String> list = Arrays.asList(input.split(","));
        int[] nums = new int[list.size()];
        for(int i=0;i<list.size();i++){
            nums[i]=Integer.parseInt(list.get(i));
        }
        
        int target = Integer.parseInt(in.nextLine());
        int result = threeSumClosest(nums,target);
        System.out.println(result);
    }
    
    public static int threeSumClosest(int[] nums, int target) {
        Arrays.sort(nums);
        int n=nums.length;
        int best=10000000;
        
        //枚举a
        for(int i=0;i<n;i++){
            //保证和上一次枚举的元素不相等
            if(i>0&&nums[i]==nums[i-1]){
                continue;
            }
            //使用双指针枚举b和c
            int j=i+1,k=n-1;
            while(j<k){
                int sum = nums[i]+nums[j]+nums[k];
                //如果和为target直接返回答案
                if(sum==target){
                    return target;
                }
                //根据差值的绝对值来更新答案
                if(Math.abs(sum-target)<Math.abs(best-target)){
                    best=sum;
                }
                if(sum>target){
                    //如果和大于target,移动c对应的指针
                    int k0=k-1;
                    //移动到下一个不相等的元素
                    while(j<k0 && nums[k0] == nums[k]){
                        --k0;
                    }
                    k=k0;
                }else{
                    //如果和小于target, 移动b对应的指针
                    int j0=j+1;
                    while(j0<k && nums[j0]==nums[j]){
                        ++j0;
                    }
                    j=j0;
                }
            }
        }
        
        
        return best;
    }

}