In a deck of cards, each card has an integer written on it.
Return true
if and only if you can choose X >= 2
such that it is possible to split the entire deck into 1 or more groups of cards, where:
X
cards.
Example 1:
Input: deck = [1,2,3,4,4,3,2,1] Output: true Explanation: Possible partition [1,1],[2,2],[3,3],[4,4].
Example 2:
Input: deck = [1,1,1,2,2,2,3,3] Output: false“ Explanation: No possible partition.
Example 3:
Input: deck = [1] Output: false Explanation: No possible partition.
Example 4:
Input: deck = [1,1] Output: true Explanation: Possible partition [1,1].
Example 5:
Input: deck = [1,1,2,2,2,2] Output: true Explanation: Possible partition [1,1],[2,2],[2,2].
Constraints:
1 <= deck.length <= 10^4
0 <= deck[i] < 10^4
struct Solution;
use std::collections::HashMap;
impl Solution {
fn gcd(a: i32, b: i32) -> i32 {
if a == 0 {
b
} else {
Self::gcd(b % a, a)
}
}
fn has_groups_size_x(deck: Vec<i32>) -> bool {
let mut hm: HashMap<i32, i32> = HashMap::new();
let mut max = 0;
for x in deck {
let count = hm.entry(x).or_default();
*count += 1;
}
for &v in hm.values() {
max = Self::gcd(max, v);
}
max >= 2
}
}
#[test]
fn test() {
let deck = vec![1, 2, 3, 4, 4, 3, 2, 1];
assert_eq!(Solution::has_groups_size_x(deck), true);
let deck = vec![1, 1, 1, 2, 2, 2, 3, 3];
assert_eq!(Solution::has_groups_size_x(deck), false);
let deck = vec![1];
assert_eq!(Solution::has_groups_size_x(deck), false);
let deck = vec![1, 1];
assert_eq!(Solution::has_groups_size_x(deck), true);
let deck = vec![1, 1, 2, 2, 2, 2];
assert_eq!(Solution::has_groups_size_x(deck), true);
}