一个有关用队列做舞伴的问题，请教下。

[qq576240289]

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef struct nodetype
{
char name[10];
char sex;
struct nodetype *next;
}nodetype;

typedef struct
{
nodetype *front;
nodetype *rear;
}linkqueue;

nodetype *enter_queue(nodetype *p, linkqueue queue)
{
nodetype *s = NULL;

s = (struct nodetype *)malloc(sizeof(struct nodetype));
strcpy(s->name, p->name);
s->sex = p->sex;
s->next = NULL;
queue.rear->next = s; 调试到这一步就不行了，请问下是怎么了？？？？？？？

return s;
}

nodetype *quit_queue(linkqueue queue)
{
nodetype *p;

printf("%s ", queue.front->name);
p = queue.front->next;
free(queue.front);

return p;

}

int main(void)
{
char ch, w;
nodetype person;
linkqueue man_queue, woman_queue;

man_queue.front = man_queue.rear = NULL;
woman_queue.front = woman_queue.rear = NULL;

printf("是否输入人员(Y/N)：");
scanf("%c", &ch);
w = getchar();

while (ch == 'Y')
{
printf("请输入姓名：\n");
scanf("%s", &person.name);
w=getchar();
printf("请输入性别(F/M)：\n");
scanf("%c", &person.sex);

if (person.sex = 'M')
{
man_queue.rear = enter_queue(&person, man_queue);
if(NULL == man_queue.front)
{
man_queue.front = man_queue.rear;
}
}
else
{
woman_queue.rear = enter_queue(&person, woman_queue);
if(NULL == woman_queue.front)
{
woman_queue.front = woman_queue.rear;
}
}

printf("是否输入人员(Y/N)：");
w = getchar();
scanf("%c", &ch);
}

printf("男女舞伴配对为：\n");

while(man_queue.front != NULL && woman_queue.front != NULL)
{
man_queue.front = quit_queue(man_queue);
woman_queue.front = quit_queue(woman_queue);
printf("\n");
}

return 0;
}

[xin_wu_hen]

queue.rear->next = s;

中，queue的rear值为NULL，NULL的next是什么？没有任何东东，你赋值可定会错了。