链表的几个问题
//链表两数相加->从头节点开始是个位依次为十百千
public static LinkedLISTsumLink(LinkedLIST heada, LinkedLIST headb){
LinkedLIST dummy =new LinkedLIST(-1,null);
LinkedLIST curr = dummy;
int carry =0;
while (heada !=null || headb !=null || carry !=0){
int avalue = heada ==null?0:heada.value;
int bvalue = headb ==null?0:headb.value;
int k = (avalue + bvalue + carry)%10;
carry = (avalue + bvalue + carry)/10;
LinkedLIST node =new LinkedLIST(k,null);
curr.next = node;
curr =curr.next;
if(heada !=null){
heada = heada.next;
}
if(headb !=null){
headb = headb.next;
}
}
return dummy.next;
}
//删除链表的倒数第N个节点
public static LinkedLISTdeleteNodeN(LinkedLIST head,int N){
LinkedLIST dummy =new LinkedLIST(-1,null);
dummy.next = head;
LinkedLIST curr = dummy;
LinkedLIST fast = head;
int k =1;
while (k<=N){
fast = fast.next;
}
while (fast !=null){
fast = fast.next;
curr = curr.next;
}
curr.next = curr.next.next;
return dummy.next;
}
//合并两个有序的链表
public static LinkedLISThebing(LinkedLIST heada, LinkedLIST headb){
if(heada ==null){
return headb;
}
if(headb ==null){
return heada;
}
if(heada.value
heada.next =hebing(heada.next,headb);
return heada;
}else {
headb.next =hebing(heada,headb.next);
return headb;
}
}
//合并K个升序链表
public static LinkedLISThebingk(ArrayList lists){
if(lists.size() ==1){
return lists.get(0);
}
if(lists.size() ==2){
return hebing(lists.get(0),lists.get(1));
}else{
LinkedLIST atemp = lists.get(0);
lists.remove(0);
return hebing(atemp,hebingk(lists));
}
}
//反转链表
public static LinkedLISTreverse(LinkedLIST heada){
if(heada ==null){
return null;
}
LinkedLIST curr = heada;
LinkedLIST pre =null;
LinkedLIST next =null;
while (curr !=null){
next = curr.next;
curr.next = pre;
pre = curr;
curr = next;
}
return pre;
}
public static LinkedLISTreverse2(LinkedLIST head){
if(head ==null){
return head;
}
LinkedLIST newhead =reverse2(head.next);
head.next.next = head;
head.next =null;
return newhead;
}
//反转前K个数莲表
public static LinkedLISTcurror =null;
public static LinkedLISTreversek(LinkedLIST head,int k){
if(k ==1){
curror = head.next;
return head;
}
LinkedLIST newhead =reversek(head.next,k-1);
head.next.next = head;
head.next =curror;
return newhead;
}
//K个一组去反转链表
public static LinkedLISTreverseKgroup(LinkedLIST head, int k){
LinkedLIST curr = head;
for(int i =0;i
curr = curr.next;
}
LinkedLIST newhead =reversek(head, k);
head.next =reverseKgroup(curr,k);
return newhead;
}
