AlgoPlan0602

# X of a deck of cards

##key idea:
- find common denominator of all counts of different numbers.
- fcd: if int !=0 find its modulus against the other int, and find the cd of the modulus against the other int again (recursive)
- compare current value with the next value, store its common denominator. as long as the cd is >= 2, should be fine.
class Solution {
    public boolean hasGroupsSizeX(int[] deck) {
        Map<Integer,Integer> map = new HashMap();
        for (int k = 0; k<deck.length;k++){
            if (map.containsKey(deck[k])){
                map.put(deck[k], map.get(deck[k])+1);
            }else{
                map.put(deck[k],1);
            }
        }
        int x= 0;
        int pre = 0;
        int temp = 0;
        for (int value: map.values()){
            System.out.print(" This value is "+ value);
            if (value <2){
                return false;
            }else{
                if (pre ==0){
                    pre = value;
                }else{
                    temp = findcd(pre,value);
                    if (temp <2){
                        return false;
                    }else{
                        x = temp;
                    }
                    pre = value;
                }
            }
        }
        return true;
    }
    //all larger  than 2
    public int findcd(int a, int b){
        if (a ==0){
            return b;
        }
        return findcd(b% a, a);
    }
}