LeetCode 16 最接近的三数之和

Posted 2021-12-14 Starzkg

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

解决方案

class Solution 
    public int threeSumClosest(int[] nums, int target) 
        int n = nums.length;
        Arrays.sort(nums);
        int abs = Integer.MAX_VALUE;
        int ans = 0;
        for (int i = 0; i < n - 2; i++) 
            if (i > 0 && nums[i] == nums[i - 1]) continue;
            for (int j = i + 1; j < n - 1; j++) 
                if (j > i + 1 && nums[j] == nums[j - 1]) continue;
                int target0 = -nums[i] - nums[j] + target;
                int l = j + 1, r = n - 1;
                while (l <= r) 
                    int mid = (l + r) >> 1;
                    int sub = target0 - nums[mid];
                    if (Math.abs(sub) < abs) 
                        ans = nums[i] + nums[j] + nums[mid];
                        abs = Math.abs(sub);
                    
                    if (sub < 0) 
                        r = mid - 1;
                     else if (sub > 0) 
                        l = mid + 1;
                     else 
                        return target;
                    
                
            
        
        return ans;