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;
}
}