1496. 判断路径是否相交

java代码：

class Solution {
    public boolean isPathCrossing(String path) {
        int x = 0;
        int y = 0;
        HashSet<String> hashSet = new HashSet<>();
        hashSet.add("0-0");
        for (int i = 0; i < path.length(); i++) {
            switch (path.charAt(i)) {
                case 'N': y++; break;
                case 'S': y--; break;
                case 'E': x++; break;
                case 'W': x--; break;
            }
            String pos = x + "-" + y;
            if (hashSet.contains(pos)) {
                return true;
            } else {
                hashSet.add(pos);
            }
        }
        return false;
    }
}