//347. Top K Frequent Elements struct Solution; /* * given an integer array 'nums' and an integer 'k', return the 'k' most frequent elements. you may * return the answer in any order. */ impl Solution { pub fn top_k_frequent(nums: Vec, k: i32) -> Vec { let mut map = std::collections::HashMap::new(); for x in nums { *map.entry(x).or_insert(0) += 1; } let mut arr = map.into_iter().collect::>(); arr.sort_by(|a,b| 1.1.cmp(&b.1)); arr.reverse(); let k = k as usize; let mut ans = vec![0;k]; for i in 0..k { ans[i] = arr[i].0; } ans } } fn main() { let n1 = vec![1,1,1,2,2,3]; let n2 = vec![1]; print!("{}", Solution::top_k_frequent(n1, 2)); //expect: [1,2] print!("{}", Solution::top_k_frequent(n2, 1)); //expect: [1] }