(Easy) Divisor Game LeetCode

import java.util.*;

class Solution {
    public boolean divisorGame(int N) {
        
        if (N ==0){
            
            return false;
        }
        
    Map<Integer, Boolean> st = new HashMap<Integer, Boolean>();
        
    st.put(1,false);
        
    for(int i = 2; i<= N; i++){
        
      boolean canWin = false;
     
      for(int j = i/2; j>0; j--){
        
        if(i%j ==0){
          
          int r = i-j;
            
          if(st.get(r) ==false){
              
            canWin=true;
            break;
          
          }
        }
        
        
      }
      st.put(i,canWin);
    }
       
       return (st.get(N)) ;
    }
}