ads1_2021/code/golang/pkg/data_structures/queues/queues.go

82 lines
1.6 KiB
Go

package queues
/* ---------------------------------------------------------------- *
* IMPORTS
* ---------------------------------------------------------------- */
import (
"fmt"
"strings"
)
/* ---------------------------------------------------------------- *
* GLOBAL VARIABLES/CONSTANTS
* ---------------------------------------------------------------- */
//
/* ---------------------------------------------------------------- *
* TYPE
* ---------------------------------------------------------------- */
type QueueInt struct {
values *[]int
}
/* ---------------------------------------------------------------- *
* METHODS stacks
* ---------------------------------------------------------------- */
func CREATE() QueueInt {
return QueueInt{}
}
func (S *QueueInt) INIT() {
S.values = &[]int{}
}
func (S QueueInt) Length() int {
if S.values == nil {
return 0
}
return len(*S.values)
}
func (S QueueInt) String() string {
if S.EMPTY() {
return "-"
}
values := []string{}
n := S.Length()
for i := n - 1; i >= 0; i-- {
value := (*S.values)[i]
values = append(values, fmt.Sprintf("%v", value))
}
return fmt.Sprintf(strings.Join(values, " -> "))
}
func (S QueueInt) EMPTY() bool {
return S.Length() == 0
}
func (S *QueueInt) ENQUEUE(x int) {
if S.values == nil {
panic("Queue not initialised!")
}
*S.values = append(*S.values, x)
}
func (S *QueueInt) FRONT() int {
if S.EMPTY() {
panic("Cannot read from empty queue!")
}
return (*S.values)[0]
}
func (S *QueueInt) DEQUEUE() {
if S.EMPTY() {
panic("Cannot remove from empty queue!")
}
*S.values = (*S.values)[1:]
}