I'm learning Rust using The Rust Programming Language. I'm trying the assignment at the end of chapter 8 — Hash Maps.

The task is:

Given a list of integers, use a vector and return the mean (average), median (when sorted, the value in the middle position), and mode (the value that occurs most often; a hash map will be helpful here) of the list.

The average value and the median were very easy for me, but I struggle solving the last part of the task. I do have a working solution (see below), but I'm sure there must be some more elegant and readable way (using the standard library?) for this.

use std::collections::HashMap; fn main() { let mut numbers = vec![42, 1, 36, 34, 76, 378, 43, 1, 43, 54, 2, 3, 43]; let avg: f32; let median: i32; let mode: i32; { // calculate average let mut sum: i32 = 0; for x in &numbers { sum = sum + x; } avg = sum as f32 / numbers.len() as f32; } { // calculate median numbers.sort(); let mid = numbers.len() / 2; median = numbers[mid]; } { // calculate mode // new HashMap let mut times = HashMap::new(); // count for x in &numbers { let cnt = times.entry(*x as usize).or_insert(0); *cnt += 1; } let mut best: (i32, i32) = (*times.iter().nth(0).expect("Fatal.").0 as i32, *times.iter().nth(0).expect("Fatal.").1 as i32); for x in times.iter() { if *x.1 > best.1 { best = (*x.0 as i32, *x.1); } } mode = best.0; } println!("AVERAGE: {}", avg); println!("MEDIAN: {}", median); println!("MODE: {}", mode) }