closest-sum-pair 0.5.0

closest_sum_pair

Fast. Clever. Free of Recursion. No while bound loops, so least runtime strikes.

It expects a sorted list. Time complexity O(N). Space complexity O(1).

Update !

From now multiple types are supported, including floating point numbers. But usize, u64, u128, i64, i128 and f64 are not supported due to f64 cannot exactly capture these values, which is relevant in this context because various types are attemped to be converted into f64 as a general type in this crate.

But all other types are supported, eg. i8, u8, i16, u16, i32, u32 and f32.

Quick Start

Due to find_pair function expects a sorted list (can be vector or array), you should sort your list using any preferred algorithm, before passing it as parameter.

The find_pair function also expects your desired sum (The sum you are looking for) If there is no exact match, it will return the closest sum possible.

use closest_sum_pair::interface::find_pair;

fn main() {
    let mut list = [-2, -4, -7, -2, -5, -13, -7];

    list.sort();

    let desired_sum = -1;

    let pair = find_pair(&mut list, desired_sum);

    println!("pair {:?}", pair) // (-2, -2)
}

Example with floating point:

use closest_sum_pair::interface::find_pair;

fn main() {
    let mut list: [f32; 7] = 
    [-2.2, -4.0, -7.9, -2.1, -5.5, -13.0, -7.1];

    list.sort_by(|a, b| a.partial_cmp(b).unwrap());

    let desired_sum = -16.7;

    let pair = find_pair(&mut list, desired_sum);

    println!("pair {:?}", pair) // (-13.0, -4.0)
}

version note: Support multiple types.