int List: Insert( int x, int i)t ∥/在链表第i个结点处插入新元素x ListNodesp- current; current= first for(k=0;k<1-1;k++)∥找第i1个结点 if current==NULL) break else current current->ink. if current== NULL & first ! NULL)( cout<<“无效的插入位置!n”; current=p; return oint List :: Insert ( int x, int i ) { //在链表第i 个结点处插入新元素x ListNode * p = current; current = first; for ( k = 0; k < i -1; k++ ) //找第 i-1个结点 if ( current == NULL ) break; else current = current->link; if ( current == NULL && first != NULL ) { cout << “无效的插入位置!\n”; current = p; return 0; }