腾讯五十题No.10 最接近的三数之和

题目链接

class Solution {
    public int threeSumClosest(int[] nums, int target) {
        int res = Integer.MAX_VALUE;
        Arrays.sort(nums);
        int sum = 0;
        for(int i = 0;i<nums.length;i++){
            if(i>0 && nums[i] == nums[i-1]) continue;
            int l = i+1,r = nums.length - 1;
            while(l<r){
                sum = nums[i] + nums[l] + nums[r];
                if(sum == target){
                    res = sum;
                }else if(Math.abs(target - sum) < Math.abs(target - res)){
                    res = sum;
                }else{
                    while(l<r && nums[l] == nums[l+1]) l++;
                    while(l<r && nums[r] == nums[r-1]) r--;
                }
                l++;
                r--;
            } 
        }
        return res;
    }
}

应该把差值定义成 Math.MAX_VALUE

class Solution {
    public int threeSumClosest(int[] nums, int target) {
        Arrays.sort(nums);
        int res = 0;
        int diff = Integer.MAX_VALUE;
        for(int i = 0; i < nums.length-2; ++i){
            int j = i+1, k = nums.length-1;
            while(j < k){
                int sum = nums[i] + nums[j] + nums[k];
                if(sum == target) return sum;
                if(Math.abs(sum-target) < diff){
                    diff = Math.abs(sum-target);
                    res = sum;
                }
                if(sum < target)
                    j++;
                else if(sum > target)
                    k--;
            }
        }
        return res;
    }
}