Poison

16. 3Sum Closest

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class Solution {
    public int threeSumClosest(int[] nums, int target) {
        int minDiff = Integer.MAX_VALUE;
        int closestSum = nums[0] + nums[1] + nums[2];

        Arrays.sort(nums);

        for (int i = 0; i < nums.length - 2; i++) {
            if (i > 0 && nums[i] == nums[i - 1]) {
                continue;
            }

            int j = i + 1, k = nums.length - 1;
            while (j < k) {
                int sum = nums[i] + nums[j] + nums[k];
                int diff = Math.abs(sum - target);
                if (diff < minDiff) {
                    minDiff = diff;
                    closestSum = sum;
                }
                
                if (sum < target) {
                    j++;
                } else if (sum > target) {
                    k--;
                } else {
                    return target;
                }
            }
        }

        return closestSum;
    }
}
Reference

16. 3Sum Closest