/*
 * @lc app=leetcode id=1207 lang=rust
 *
 * [1207] Unique Number of Occurrences
 *
 * https://leetcode.com/problems/unique-number-of-occurrences/description/
 *
 * algorithms
 * Easy (71.22%)
 * Total Accepted:    37.1K
 * Total Submissions: 52K
 * Testcase Example:  '[1,2,2,1,1,3]'
 *
 * Given an array of integers arr, write a function that returns true if and
 * only if the number of occurrences of each value in the array is unique.
 * 
 * 
 * Example 1:
 * 
 * 
 * Input: arr = [1,2,2,1,1,3]
 * Output: true
 * Explanation: The value 1 has 3 occurrences, 2 has 2 and 3 has 1. No two
 * values have the same number of occurrences.
 * 
 * Example 2:
 * 
 * 
 * Input: arr = [1,2]
 * Output: false
 * 
 * 
 * Example 3:
 * 
 * 
 * Input: arr = [-3,0,1,-3,1,1,1,-3,10,0]
 * Output: true
 * 
 * 
 * 
 * Constraints:
 * 
 * 
 * 1 <= arr.length <= 1000
 * -1000 <= arr[i] <= 1000
 * 
 * 
 */
impl Solution {
    pub fn unique_occurrences(arr: Vec<i32>) -> bool {
        let eye = vec_counter(arr);
        let mut x:HashSet<i32> = HashSet::new(); 
        for k in eye.keys(){
            x.insert(eye[k]);
        }
        eye.len() == x.len()
    }
}
// pub structSolution; 
use std::collections::HashMap;
use std::collections::HashSet;
use std::fmt::Debug;
use std::hash::Hash;

#[allow(dead_code)]
pub fn vec_counter(arr: Vec<i32>) -> HashMap<i32, i32> {
    let mut c = HashMap::new(); 
    for n in arr { *c.entry(n).or_insert(0) += 1; }
    c 
}

#[allow(dead_code)]
pub fn print_map<K: Debug + Eq + Hash, V: Debug>(map: &HashMap<K, V>) {
    for (k, v) in map.iter() {
        println!("{:?}: {:?}", k, v);
    }
}

#[allow(dead_code)]
pub fn say_vec(nums: Vec<i32>){
	println!("{:?}", nums);
}

#[allow(dead_code)]
pub fn char_frequency(s: String) -> HashMap<char, i32> {
    let mut res:HashMap<char, i32> = HashMap::new(); 
    for c in s.chars(){
        *res.entry(c).or_insert(0) += 1;
    }
    res 
}