【力扣】16. 最接近的三數之和

AC代碼

排序+雙指針

    public int threeSumClosest(int[] nums, int target) {
            Arrays.sort(nums);
            int bestNum = nums[0] + nums[1] + nums[2];
            for (int i = 0;i < nums.length -2;i++) {
                int l = i + 1;
                int r = nums.length - 1;
                while (l < r) {
                    while(i >= l || l > r) l++;
                    if (Math.abs(bestNum - target) > Math.abs(nums[i] + nums[r] + nums[l] - target))
                    bestNum = nums[i] + nums[r] + nums[l];
                    int tmp = nums[i] + nums[r] + nums[l] - target;
                    //選擇最優的
                    if (tmp > 0) {
                        r--;
                    } else if (tmp < 0){
                        l++;
                    } else {
                        bestNum = nums[i] + nums[r] + nums[l];
                        break;
                    }
                }
            }
            return bestNum;
    }