hdoj_5643 King's Game(约瑟夫环问题变种)----超时版本（自己模拟的循环链表）

我很搞笑的用C++写了个C版本的双向循环链表(虽然是超时的，但是很久没有写过链表的，所以试一试)。。。

#include
#include
#include
#include
using namespace std;

struct node {
	int num;
	struct node * pre, * next;
};

struct node * create(struct node * head, int n) {
	struct node * p, * q;
	for(int i = 1; i <= n; i++) {
		q = (struct node *)malloc(sizeof(struct node));
		q->num = i;
		if(head == NULL) {  //head为空  还没有节点。 
			head = q;
			q->next = q;
			q->pre = q;
		}
		else {  //p后面加了q 
			q->next = p->next;
			q->pre = p;
			p->next->pre = q;
			p->next = q;
		}
		p = q;	
	}
	return p->next;   //返回第一个节点 
}

struct node * solve(struct node * head, int time) {
	struct node * p, * q;
	int cnt = 1;
	p = q = head->pre;
	while(cnt <= time) {
		p = p->next;
		cnt++;
	}
	p->next->pre = p->pre;
	p->pre->next = p->next;
	q = p->next;
	free(p);
	return q;
}
/*
void Print(struct node * head, int m) {
	struct node * p;
	for(int i = 1; i <= m; i++) {
		p = p->next;
	}
}
*/
int main() {
	int cas; cin >> cas;
	while(cas--) {
		int N; cin >> N;
		struct node * head = NULL;
		head = create(head, N);
		for(int i = 1; i < N; i++) head = solve(head, i);
		cout << head->num << endl;
	}
	return 0;
}