Description

class Solution {
    bool canWin(vector<int>& count, int sum, int turn) {
        if(count[0] + count[1] + count[2] == 0) {
            if(turn == 1) return true;
            return false;
        }

        if(count[0] > 0) {
            --count[0];
            return !canWin(count, sum, 1 - turn);
        } else if(sum % 3 == 1) {
            if(count[1] > 0) {
                --count[1];
                return !canWin(count, sum + 1, 1 - turn);
            }
            return false;
        } else {
            if(count[2] > 0) {
                --count[2];
                return !canWin(count, sum + 2, 1 - turn);
            }
            return false;
        }
    }
public:
    bool stoneGameIX(vector<int>& stones) {
        vector<int> count(3, 0);

        for(int stone: stones) {
            ++count[stone % 3];
        }

        auto tmp = count;
        // 0 for Alice, 1 for Bob, next turn should be Bob
        if(count[1] > 0) {
            --tmp[1];
            if(!canWin(tmp, 1, 1)) return true;
        }

        tmp = count;
        if(count[2] > 0) {
            --tmp[2];
            if(!canWin(tmp, 2, 1)) return true;
        }

        return false;
    }
};