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:
Each group has exactly X cards.
All the cards in each group have the same integer.
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
public class Solution {
public bool HasGroupsSizeX(int[] deck) {
if(deck.Length<=1){
return false;
}
var map = new Dictionary<int,int>();
for(int i=0;i<deck.Length;i++){
if(map.ContainsKey(deck[i])){
map[deck[i]]++;
}
else{
map.Add(deck[i],1);
}
}
int res = 0;
foreach(var item in map){
res = gcd(item.Value,res);
}
return res>1;
}
private int gcd(int a, int b){
if(b>0){
return gcd(b,a%b);
}
return a;
}
}
Time Complexity: O(n)
Space Complexity: O(n)