Clippy lints.

Also restored standard module use to where it was.

src/main.rs

@@ -4,14 +4,14 @@
 #![allow(clippy::match_overlapping_arm)]
 #![allow(clippy::new_without_default)]
 
+use std::io::Write;
+
 pub mod solutions;
 pub mod utils;
 
 #[cfg(test)]
 mod tests;
 
-use std::io::Write;
-
 /// Execute the solution (if available) of the specified problem. Also measure
 /// its running time.
 ///

src/solutions/distinct_powers.rs

@@ -8,7 +8,7 @@ use crate::utils;
 /// * `primes` - Prime numbers to use to calculate the exponent.
 ///
 /// -> Exponent.
-fn exponent(mut num: i64, primes: &Vec<i64>) -> i64 {
+fn exponent(mut num: i64, primes: &[i64]) -> i64 {
     // Calculate the greatest exponent of every prime in the given number.
     let mut exponents = vec![0i64; primes.len()];
     let mut gcd = 0;