16.3Sum Closest¶
Tags: Array
Medium
Links: https://leetcode.com/problems/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).
Answer:
class Solution {
public:
int threeSumClosest(vector<int>& nums, int target) {
int result = 0;
int gap = INT_MAX;
sort(nums.begin(), nums.end());
for (int i = 0; i < nums.size() - 2; ++i){
if (i > 0 && nums[i] == nums[i - 1]) continue;
int j = i + 1, k = nums.size() - 1;
while (j < k){
int tmp = nums[i] + nums[j] + nums[k];
if (abs(tmp - target) < gap){
result = tmp;
gap = abs(tmp - target);
}
if (tmp < target)
++j;
else
--k;
}
}
return result;
}
};