UVa-133-The Dole Queue

AOAPC
I: Beginning Algorithm Contests (Rujia Liu) :: Volume
2. Data Structures :: Lists



// 133 - The Dole Queue
#include <cstdio>
#include <cstdlib>

typedef struct node
{
int num;
struct node* pre;
struct node* next;
}*ptr;

ptr creatnode(int elem)
{
ptr temp;
temp = (struct node*)malloc(sizeof(struct node));
if(temp == NULL)
exit(EXIT_FAILURE);
temp->num = elem;
temp->pre = NULL;
temp->next = NULL;
return temp;
}

void creatlist(ptr* x, ptr* y, int n)
{
ptr head, temp;
head = creatnode(1);
temp = head;
for(int i = 2; i <= n; i++)
{
temp->next = creatnode(i);
temp->next->pre = temp;
temp = temp->next;
}
temp->next = head;
head->pre = temp;

*x = head;
*y = temp;
}

void deletenode(ptr t)
{
ptr temp = t;
temp->next->pre = t->pre;
temp->pre->next = t->next;
printf("%3d", t->num);
free(t);
}

int main(void)
{
int i, n, k, m, cnt;
ptr x, y, x_t, y_t;
while(scanf("%d%d%d", &n, &k, &m) && n)
{
cnt = 0;
creatlist(&x, &y, n);

while(cnt != n)
{
for(i = 1; i < k; i++)
x = x->next;
for(i = 1; i < m; i++)
y = y->pre;

if(x == y)
{
x_t = x->next;
y_t = y->pre;
deletenode(x);
cnt++;
}
else if(x->next == y)
{
x_t = y->next;
y_t = x->pre;
deletenode(x);
deletenode(y);
cnt += 2;
}
else
{
x_t = x->next;
y_t = y->pre;
deletenode(x);
deletenode(y);
cnt += 2;
}
x = x_t;
y = y_t;

if(cnt != n)
printf(",");
}
printf("\n");
}
return 0;
}