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  • [LeetCode] 16. 3Sum Closest

    传送门

    Description

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

    For example, given array S = {-1 2 1 -4}, and target = 1.
    
    The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
    

      

    思路

    题意:给出一串整数值序列,求取最接近目标值的三个数的和

    题解:按照3Sum的思路然后更新与目标值最接近的三个数的和

    class Solution {
        //22ms
        public int threeSumClosest(int[] nums, int target) {
            Arrays.sort(nums);
            int res = 0,min = Integer.MAX_VALUE;
            int len = nums.length;
            for (int i = 0;i < len - 2;i++){
                int goal = target - nums[i];
                int left = i + 1,right = len - 1;
                while (left < right){
                    int sum = nums[i] + nums[left] + nums[right];
                    if (sum == target){
                        return sum;
                    }
                    if (Math.abs(target - sum) < min){
                        res = sum;
                        min = Math.abs(target - sum);
                    }
                    if (nums[left] + nums[right] < goal){
                        left++;
                    }else if (nums[left] + nums[right] > goal){
                        right--;
                    }
                }
            }
            return res;
        }
    }
    

      

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  • 原文地址:https://www.cnblogs.com/ZhaoxiCheung/p/LeetCode-3SumClosest.html
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