Simplify Path

all the possible

public class Solution {
    public String simplifyPath(String path) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        Stack<String> mystack = new Stack<String>();
        char[] mystring = path.toCharArray();
        for(int i=0; i<mystring.length; i++)
        {
            if(mystring[i] == '/' && i + 1 < mystring.length && mystring[i+1] == '.'&&i + 2 < mystring.length && mystring[i+2] == '.')
            {
                i+=2;
                if(!mystack.isEmpty())
                    mystack.pop();
            }
            else if(mystring[i] == '/' && i + 1 < mystring.length && mystring[i+1] == '.'&&i + 2 < mystring.length && mystring[i+2] == '/')
            {
                i+=1;
            }
            
            else if(mystring[i] == '/' && i + 1 < mystring.length && mystring[i+1] == '.' && i + 2 < mystring.length && isChar(mystring[i+2])){
                int count = 2;
                StringBuilder tmp = new StringBuilder();
                tmp.append('.');
                while((i+count) < mystring.length && isChar(mystring[i+count])){
                    tmp.append(mystring[i+count]);
                    count++;
                }
                mystack.push(tmp.toString());
                i+=(count-1);
            }
            
            else if(mystring[i] == '/' && i + 1 < mystring.length && mystring[i+1] == '/')
                continue;
            else if(mystring[i] == '/' && i + 1 < mystring.length && isChar(mystring[i+1])){
                int count = 1;
                StringBuilder tmp = new StringBuilder();
                while((i+count) < mystring.length && isChar(mystring[i+count])){
                    tmp.append(mystring[i+count]);
                    count++;
                }
                mystack.push(tmp.toString());
                i+=(count-1);
            }
        }
        if(mystack.isEmpty())
            return "/";
        return print(mystack);
    }
    
    private String print(Stack<String> mystack)
    {
        if(mystack.isEmpty())
            return "";
        String tmp = mystack.pop();
        return print(mystack) + "/" + tmp;
    }
    private boolean isChar(char mychar){
        if((mychar >= 'a' && mychar <= 'z') || mychar == '_' || (mychar >= '0' && mychar <= '9') || (mychar >= 'A' && mychar <= 'Z'))
            return true;
        return false;
    }
}