Tue. Aug 13th, 2024

# LeetCode – Strings – Path Crossing

#### ByKnight Coderz

Aug 13, 2020

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