采用鄰接表存儲結構，編寫一個判別無向圖中任意給定的
兩個頂點之間是否存在一條長度為k的簡單路徑的算法。

實現下列函數：
Status?SinglePath（ALGraph?g?VertexType?sv?VertexType?tv
??????????????????int?k?char?*sp）;
/*?Judge?whether?it?exists?a?path?from?sv?to?tv?with?length?k?*/
/*?in?graph?g?return?path?using?string?sp?if??exists.????????*/

圖的鄰接表以及相關類型、函數和輔助變量定義如下：
Status?visited[MAX_VERTEX_NUM];
typedef?char??StrARR[100][MAX_VERTEX_NUM+1];
typedef?char?VertexType;
typedef?struct?ArcNode?{
????int?adjvex;
????struct?ArcNode?*nextarc;
}?ArcNode;

typedef?struct?VNode?{
????VertexType?data;
????ArcNode??*firstarc;
}?VNode?AdjList[MAX_VERTEX_NUM];

typedef?struct?{
????AdjList?vertices;
????int?vexnum?arcnum;
}?ALGraph;

int?LocateVex（Graph?g?VertexType?v）;
vo