Given a string path, where path[i] = 'N', 'S', 'E' or 'W', each representing moving one unit north, south, east, or west

[answerhappygod]

Given a string path, where path = '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 have previously
visited. Return false otherwise.
class Solution { public: bool isPathCrossing(string path) { }
};