Mnemonic search + state compression leetcode four hundred and sixty-four

 public static boolean canIWin(int maxChoosableInteger, int desiredTotal) {
        int[] dp=new int[1<<maxChoosableInteger];// Will you win in a certain state 
        // The sum is less than the target , Will lose 
        if(desiredTotal>(1+maxChoosableInteger)*maxChoosableInteger/2) return false;
        return dfs(dp,0,maxChoosableInteger,desiredTotal,0);
 
    }
    static boolean dfs(int[] dp,int sum,int maxChoosableInteger,int desiredTotal,int state){
        // If the current state has been traversed , return 
        if(dp[state]!=0) {
            if(dp[state]==1)
                return true;
            else return false;
        }
        // Look for unselected numbers 
            for(int j=0;j<maxChoosableInteger;j++){
                if((state&(1<<j))!=0) continue;
                // If the number meets the conditions, you will win 
                if(sum+j+1>=desiredTotal){
                    dp[state]=1;
                    return true;
                }
                // Otherwise, judge whether the other party will lose 
                if(!dfs(dp,sum+j+1,maxChoosableInteger,desiredTotal,state|(1<<j))){
                    dp[state]=1;
                    return true;
                }
 
            }
            // You can't make yourself win or your opponent lose , Then you lose 
            dp[state]=-1;
            return false;
    }