//2442. Count Number of Distinct Integers After Reverse Operations use std::collections::HashSet; struct Solution; /* * array nums contains positive integers * take each integer in array and reverse its digits (eg. 13 -> 31) * then *add* it to end of array. return number of distinct integers. * [1,13,10,12,31] becomes [1,13,10,12,31,1,31,1,21,13] * and total num of distinct ints = 6 */ impl Solution { pub fn count_distinct_integers(nums: Vec) -> i32 { let mut hs: HashSet = nums.iter().map(|&n| Self::reverse(n)).collect(); hs.extend(nums.iter()); hs.len() as i32 } fn reverse(mut n: i32) -> i32 { let mut rev: i32 = 0; while n > 0 { rev *= 10; rev += n % 10; n /= 10; } rev } } fn main() { let nums1 = vec![1,13,10,12,31]; let nums2 = vec![2,2,2]; println!("{}", Solution::count_distinct_integers(nums1)); //expect: 6 println!("{}", Solution::count_distinct_integers(nums2)); //expect: 1 }