合并单链表-无头结点

mergeList.cpp

Node *MergeLists(Node *headA, Node *headB) {
    if (headA == NULL && headB == NULL) {
        return NULL;
    } else if (! headA && headB) {
        return headB;
    } else if (headA && !headB) {
        return headA;
    } else {
        Node *ptrToA = headA, *ptrToB = headB;
        Node *cur = (Node *)malloc(sizeof(Node));
        Node *head = cur;
        while(ptrToA && ptrToB) {
            while(ptrToA && ptrToB && (ptrToA->data < ptrToB->data)) {
                Node *newCell = (Node *)malloc(sizeof(Node));
                newCell->data = ptrToA->data;
                cur->next = newCell;
                cur = newCell;
                ptrToA = ptrToA->next;
            }
            while(ptrToA && ptrToB && (ptrToA->data > ptrToB->data)) {
                Node *newCell = (Node *)malloc(sizeof(Node));
                newCell->data = ptrToB->data;
                cur->next = newCell;
                cur = newCell;
                ptrToB = ptrToB->next;
            }
            while(ptrToA && ptrToB && (ptrToA->data == ptrToB->data)) {
                Node *newCell = (Node *)malloc(sizeof(Node));
                newCell->data = ptrToA->data;
                cur->next = newCell;
                cur = newCell;
                ptrToA = ptrToA->next;
                ptrToB = ptrToB->next;
            }
        }
        if(!ptrToA && ptrToB) {
            while(ptrToB) {
                Node *newCell = (Node *)malloc(sizeof(Node));
                newCell->data = ptrToB->data;
                cur->next = newCell;
                cur = newCell;
                ptrToB = ptrToB->next;
            }
            cur->next = NULL;
        } else if(ptrToA && !ptrToB) {
            while(ptrToA) {
                Node *newCell = (Node *)malloc(sizeof(Node));
                newCell->data = ptrToA->data;
                cur->next = newCell;
                cur = newCell;
                ptrToA = ptrToA->next;
            }
            cur->next = NULL;
        } else if (!ptrToA && !ptrToB ) {
            cur->next = NULL;
        }
        return head->next;
    }
}