LeetCode16. 3Sum Closest instead of three and the number of

16.3Sum Closest closest to the target value and the number of three

3Sum Closest

Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the three integers. You may assume that each input would have exactly one solution.

Example:

Given array nums = [-1, 2, 1, -4], and target = 1.

The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

And three modified based on the number of

Problem-solving ideas and LeetCode15 3Sum three digital sum is the same, just different when processed. Also the same manner employed in the double pointer. Each time the pointer moves have to compare the current value of the distance to the nearest previous value and the target value of the magnitude of distance, comparing a record for the next closest target.

class Solution {
    public int threeSumClosest(int[] nums, int target) {
        Arrays.sort(nums);
        int numsLen = nums.length;
        int result = nums[0] + nums[1] + nums[2];
        for(int i = 0 ; i < numsLen - 2; i++){
            if(i > 0 && nums[i] == nums[i-1]){
                continue;
            }            
            int left = i+ 1;
            int right = nums.length -1;
            while(left < right){
                int sum = nums[i] + nums[left] + nums[right];
                if(sum < target){
                    if(Math.abs(target - sum) < Math.abs(target - result)){
                        result = sum;
                    }
                    left++;
                 while(left < right && nums[left] == nums[left - 1]){
                    left++;
                }
                } else if(sum > target){
                    if(Math.abs(target - sum) < Math.abs(target - result)){
                        result = sum;
                    }
                    right--;
                while(left < right && nums[right] == nums[right + 1]){
                    right--;
                }
                } else {
                    return target;
                }
            }
        }
        return result;
    }
}