Problem

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

Example 1:

Input: nums = [-1,2,1,-4], target = 1
Output: 2
Explanation: The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

Constraints:

• ​​3 <= nums.length <= 10^3​​
• ​​-10^3 <= nums[i] <= 10^3​​
• ​​-10^4 <= target <= 10^4​​

Solution

impl Solution {
    pub fn three_sum_closest(nums: Vec<i32>, target: i32) -> i32 {
        let mut temp = nums.clone();
        temp.sort();
        let (mut l, mut i, mut r): (i32, i32, i32) = (0, 1, 0);
        let mut sum: i32 = 0;
        let mut ret: i32 = 99999999;
        while (i as usize) < temp.len()-1 {    
            l = i - 1;
            r = i + 1;
            while l >= 0 && (r as usize) < temp.len() {
                sum = temp[i as usize ] + temp[l as usize ] + temp[r as usize];
                if sum == target {
                    return sum;
                }
                if sum > target {
                    l -= 1;
                } else {
                    r += 1;
                }
                if (sum - target).abs() < (ret - target).abs() {
                    ret = sum;
                }
            } 
            i += 1;
        }
        ret
    }
}