BJFUOJ-419

链表的循环右移

#include<iostream>
using namespace std;
typedef struct ListNode {
	int val;
	ListNode* next;
	ListNode():val(0),next(nullptr){}
	ListNode(int x):val(x),next(nullptr){}
}ListNode,*LinkList;

LinkList TailInsert(int n) {
	ListNode* head = new ListNode;
	ListNode* r = head;
	for (int i = 0; i < n; i++) {
		int x;
		cin >> x;
		ListNode* p = new ListNode(x);
		r->next = p;
		r = p;
	}
	r->next = nullptr;
	return head;
}
//1 2 3 4 5   2 % 5
// 0 1 2    4 % 3 = 1
void movek(LinkList L,int k) {
	ListNode* p = L->next;
	ListNode* pre = L;
	ListNode* r = p;
	int n = 0;
	while (r->next != nullptr) { //找到倒数第一个结点
		r = r->next;
		n++;
	}
	n++;
	k = k % n;
	if (k == 0) {
		return;
	}
	ListNode* q = p;
	while (q && k) {
		if (q != nullptr) q = q->next;
		k--;
	}
	if (k != 0) {
		return;
	}
	while (q) {
		pre = p;
		p = p->next;
		q = q->next;
	}
	//p就是倒数第k个结点
	r->next = L->next;
	L->next = p;
	pre->next = nullptr;
}
void print(LinkList L) {
	ListNode* p = L->next;
	while (p) {
		cout << p->val;
		if (p->next != nullptr) cout << " ";
		p = p->next;
	}
	cout << endl;
}
int main() {
	
	int n;
	while (cin >> n && n != 0) {
		LinkList L = TailInsert(n);
		int k; cin >> k;
		movek(L,k);
		print(L);
	}
	return 0;
}