LeetCode - Strings - Path Crossing

Given a string path, where path[i] = 'N''S''E' or 'W', each representing moving one unit north, south, east, or west, respectively. You start at the origin (0, 0) on a 2D plane and walk on the path specified by path.

Return True if the path crosses itself at any point, that is, if at any time you are on a location you've previously visited. Return False otherwise.

 

Example 1:

Input: path = "NES"
Output: false 
Explanation: Notice that the path doesn't cross any point more than once.

Example 2:

Input: path = "NESWW"
Output: true
Explanation: Notice that the path visits the origin twice.

 

Constraints:

  • 1 <= path.length <= 10^4
  • path will only consist of characters in {'N', 'S', 'E', 'W}

 

class Solution {
    public boolean isPathCrossing(String path) {
       int x = 0;
       int y = 0;
       List<String> pathList = new ArrayList<String>(); 
       pathList.add(x+""+y);
       for(int i=0;i<path.length();i++){
           //System.out.println(path.charAt(i));
           String direction = path.charAt(i)+"";
           if("N".equals(direction)){
               y++;
           }else if("S".equals(direction)){
               y--;
           }else if("E".equals(direction)){
               x++;
           }else{
               x--;
           }
           if(pathList.contains(x+""+y)) 
               return true;
           else
               pathList.add(x+""+y);

       }
       //System.out.println(pathList);
       return false;
    }
}

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