带头结点有序单链表的合并
typedef int Item;typedef struct node{ Item item; struct node *next;}Node,*List;void merge1(List la, List lb, List *lc){ Node *pa,*pb,*pc; pa=la->next; pb=lb->next; pc=(*lc)=la; while(pa && pb){ if(pa->item <= pb->item){ pc->next=pa; pc=pa; pa=pa->next; }else{ pc->next=pb; pc=pb; pb=pb->next; } } pc->next=pa?pa:pb; free(lb);}/*two non-headnode list merge*/List __merge(List la, List lb){ List lc; if(la==NULL) return lb; if(lb==NULL) return la; if(la->item <= lb->item){ lc=la; lc->next=__merge(la->next,lb); }else{ lc=lb; lc->next=__merge(la,lb->next); } return lc;}List merge2(List la, List lb){ if(la->next==NULL){ free(la); return lb; } if(lb->next==NULL){ free(lb); return la; } List lc=malloc(sizeof(Node)); lc->next=__merge(la->next,lb->next); free(la); free(lb); return lc;}?