week6 464. Can I Win

public class Solution {
    public boolean canIWin(int maxChoosableInteger, int desiredTotal) {
        if (desiredTotal <= 0){
            return true;
        }
        if (maxChoosableInteger * (maxChoosableInteger + 1) / 2 < desiredTotal){
            return false;
        }
        return canIWin(desiredTotal, maxChoosableInteger, 0, new HashMap<>());
    }
    private boolean canIWin(int total, int n, int state, HashMap<Integer,Boolean>cache)
        if(total <= 0){
            return false;
        }
    if (cache.containsKey(state)){
        return cache.get(state);
    }
    
    for(int i = 0; i < n; i++){
        if((state & (1 << i)) != 0){
            continue;
        }
        if (!canIWin(total-(i+1), n, state | (1<<i), cache)){
            cache.put(state, ture);
            return true;
        }
    }
    
    cache.put(state, false);
    return false;
}