Comments

Author: Santo

Linkedlist.go

@@ -2,43 +2,52 @@ package main
 
 import "fmt"
 
+/* v is the value of node; next is the pointer to next node */
 type node struct {
 	v int
 	next *node
 }
 
+/* first node, called head. It points from first node to last node */
 var head *node = nil
 
 func (l *node) pushFront(val int) *node {
+	/* if there's no nodes, head points to l (first node) */
 	if head == nil {
 		l.v = val
 		l.next = nil
 		head = l
 		return l
 	} else {
+		/* create a new node equals to head */
 		nnode := new(node)
 		nnode = head
-
+		/* create a second node with new value and `next -> nnode`
+		*  is this way, nnode2 is before nnode
+		*/
 		nnode2 := &node {
 			v: val,
 			next: nnode,
 		}
+		/* now head is equals nnode2 */
 		head = nnode2
 		return head
 	}
 }
 
 func (l *node) pushBack(val int) *node {
+	/* if there's no nodes, head points to l (first node) */
 	if head == nil {
 		l.v = val
 		l.next = nil
 		head = l
 		return l
 	} else {
+		/* read all list to last node */
 		for l.next != nil {
 			l = l.next
 		}
-
+		/* allocate a new portion of memory */
 		l.next = new(node)
 		l.next.v = val
 		l.next.next = nil
@@ -50,9 +59,11 @@ func (l *node) popFront() *node {
 	if head == nil {
 		return head
 	}
-
+	/* create a new node equals to first node pointed by head */
 	cpnode := new(node)
 	cpnode = head.next
+	
+	/* now head is equals cpnode (second node) */
 	head = cpnode
 
 	return head
@@ -62,27 +73,30 @@ func (l *node) popBack() *node {
 	if head == nil {
 		return head
 	}
-
+	/* create a new node equals to head */
 	cpnode := new(node)
 	cpnode = head
-
+	
+	/* read list to the penultimate node */
 	for cpnode.next.next != nil {
 		cpnode = cpnode.next
 	}
-
+	/* the penultimate node points to null. In this way the last node is deleted */
 	cpnode.next = nil
 	return head
 }
 
 func main() {
 	lista := new(node)
-	lista.pushBack(25).pushBack(24).pushBack(32)
-	lista.pushBack(56)
-	lista.pushFront(36)
-	lista.popFront()
-	lista.popBack()
+	lista.pushBack(25).pushBack(24).pushBack(32) /* lista: 25 24 32 */
+	lista.pushBack(56) /* lista: 25 24 32 56 */
+	lista.pushFront(36) /* lista: 36 25 24 32 56 */
+	lista.popFront() /* lista: 25 24 32 56 */
+	lista.popBack() /* lista: 25 24 32 */
+	
+	/* read the list until head is not nil */
 	for head != nil {
 		fmt.Printf("%d ",head.v)
-		head = head.next
+		head = head.next /*head points to next node */
 	}
 }