给定一个数组arr，可能有正、有负、有0，无序。
只能挑选两个数字，想尽量让两个数字加起来的绝对值尽量小。
返回可能的最小的值。
排序，双指针。
代码用rust编写。代码如下：
fn main() {
let mut arr: Vec<i32> = vec![-8, -5, -2, -1, 0, 1, 7, 9];
let ans = min_sumabs3(&mut arr);
println!("ans = {}", ans);
}
fn min_sumabs3(arr: &mut Vec<i32>) -> i32 {
if arr.len() < 2 {
return -1;
}
arr.sort();
let n = arr.len() as i32;
let mut split: i32 = -1;
for i in 0..n {
if arr[i as usize] >= 0 {
split = i;
break;
}
}
if split == 0 {
return arr[0] + arr[1];
}
if split == -1 {
return -arr[(n - 2) as usize] - arr[(n - 1) as usize];
}
let mut ans = 2147483647;
if split + 1 < n {
ans = arr[split as usize] + arr[(split + 1) as usize];
}
if split - 2 >= 0 {
ans = get_min(ans, -arr[(split - 1) as usize] - arr[(split - 2) as usize]);
}
let mut r = n - 1;
for l in 0..split {
ans = get_min(ans, abs(arr[l as usize] + arr[r as usize]));
while r - 1 >= split
&& abs(arr[l as usize] + arr[r as usize])
>= abs(arr[l as usize] + arr[(r - 1) as usize])
{
r -= 1;
ans = get_min(ans, abs(arr[l as usize] + arr[r as usize]));
}
}
return ans;
}
fn get_min<T: Clone + Copy + std::cmp::PartialOrd>(a: T, b: T) -> T {
if a < b {
a
} else {
b
}
}
fn abs(a: i32) -> i32 {
if a < 0 {
-a
} else {
a
}
}执行结果如下：
