PI Pratica 30-03

#include <stdio.h>

// [ , , , , ]  MAX
// [1, , , , ]

// [1,4,17, , ] front = 0, length = 3
    // dequeue -> tirei o 1 da fila

// [1,4,17, , ] front = 1, length = 2

    // dequeue -> tirei o 4 da fila
// [1,4,17, , ] front = 2, length = 1

// inseri 23 e 55

// [1,4,17,23,55] front = 2, length = 3

// inserir 47
// [47,4,17,23,55] front = 2, length = 4

//inserir 39
// [47,39,17,23,55] front = 2, length = 5


//[38,4,17,23,55] front = 4, length = 2;



#define MAX 5

struct staticqueue{
  int front;
  int length;
  int values[MAX];
  };

typedef struct staticqueue *SQueue;

void SinitSQueue(SQueue q){
    q->front = 0;
    q->length = 0;
  }

int Senqueue(SQueue q, int x){
  if(q->length == MAX) return -1;

  q->values[(q->length + q->front)%MAX] = x;
  q->length++;

  return 0;
  }

int Sdequeue(SQueue q, int *x){
  if(q->length == 0) return -1;

  *x = q->values[q->front];

  q->length--;
  q->front = (q->front+1)%MAX;
  return 0;
  }

int Sfront(SQueue, int *x){
  if(q->length == 0) return -1;

  *x = q->values[q->front];
  return 0;
  }

int main() {
  struct staticqueue s1;
  SQueue s = &s1;
  int x;

  SinitSQueue(s);
  Senqueue(s,29);
  Senqueue(s,67);
  Senqueue(s,7);
  Senqueue(s,35);
  Senqueue(s,9);

  Sdequeue(s,&x);
  Sdequeue(s,&x);
  Sdequeue(s,&x);
  Sdequeue(s,&x);

  Senqueue(s,50);
  Sdequeue(s,&x);

  return 0;
}