图4——广度优先

【原理】

STEP1.开始节点入队列

STEP2.将当前队列出列，出列的节点判断是否有子节点，每个子节点入队列。

STEP3.只要队列没空，重复STEP2

【实现】

        public List<CVertex> BreadFirstSearch()
        {
            List<CVertex> lstRes = new List<CVertex>();

            Queue<int> oQueue = new Queue<int>();
            this.m_lstVertex[0].IsVisited = true;
            oQueue.Enqueue(0);
            lstRes.Add(this.m_lstVertex[0]);
            int iVertexIndex, iAdjVertexIndex;
            while (oQueue.Count > 0)
            {
                iVertexIndex = oQueue.Dequeue();
                iAdjVertexIndex = _GetAdjUnvisitedVertexIndex(iVertexIndex);
                while (RET_ISNOT_NOSUCCSSOR_VERTEX != iAdjVertexIndex)
                {
                    this.m_lstVertex[iAdjVertexIndex].IsVisited = true;
                    lstRes.Add(this.m_lstVertex[iAdjVertexIndex]);
                    oQueue.Enqueue(iAdjVertexIndex);
                    iAdjVertexIndex = _GetAdjUnvisitedVertexIndex(iVertexIndex);
                }
            }

            foreach (var oVertex in this.m_lstVertex)
            {
                oVertex.IsVisited = false;
            }

            return lstRes;
        }