3Sum Closest
Given an array nums
of n integers and an integer target
, find three integers in nums
such that the sum is closest to target
. Return the sum of the three integers. You may assume that each input would have exactly one solution.
Example:
Given array nums = [-1, 2, 1, -4], and target = 1. The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
C++:
class Solution { public: int threeSumClosest(vector<int>& nums, int target) { int result; if (nums.size() < 3) return -1; sort(nums.begin(), nums.end()); int abs_diff = INT_MAX; for (int i = 0; i < nums.size() - 2; i++){ for (int j = i + 1, k = nums.size() - 1; j < k;){ int sum = nums[i] + nums[j] + nums[k]; if (abs_diff>abs(target - sum)){ abs_diff = abs(target - sum); //更新最小绝对值差 result=sum; } if (sum < target){ while (nums[++j] == nums[j - 1] && j < k); } else{ while (nums[--k] == nums[k + 1] && j < k); } } } return result; } };