From 089acbcc346904924e44fde4e3cdf9fbf7a6c526 Mon Sep 17 00:00:00 2001
From: eson <474420502@qq.com>
Date: Thu, 6 Jun 2019 02:17:35 +0800
Subject: [PATCH] =?UTF-8?q?arraylist=20remove=20=E6=B5=8B=E8=AF=95?=
 =?UTF-8?q?=E5=AE=8C=E6=88=90?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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---
 list/arraylist/arraylist.go      | 15 ++++++++---
 list/arraylist/arraylist_test.go | 46 ++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/list/arraylist/arraylist.go b/list/arraylist/arraylist.go
index 89f58b7..5cae300 100644
--- a/list/arraylist/arraylist.go
+++ b/list/arraylist/arraylist.go
@@ -47,7 +47,7 @@ func (l *ArrayList) Size() uint {
 func (l *ArrayList) shrink() {
 
 	if l.size <= listMinLimit {
-		log.Panic("list size is over listMaxLimit", listMinLimit)
+		return
 	}
 
 	if l.size <= l.shrinkSize {
@@ -137,7 +137,7 @@ func (l *ArrayList) Index(idx uint) (interface{}, bool) {
 
 func (l *ArrayList) Remove(idx uint) (result interface{}, isfound bool) {
 
-	if idx < l.size {
+	if idx >= l.size {
 		return nil, false
 	}
 
@@ -145,9 +145,16 @@ func (l *ArrayList) Remove(idx uint) (result interface{}, isfound bool) {
 
 	isfound = true
 	result = l.data[offset]
-	l.data[offset] = nil // cleanup reference
+	// l.data[offset] = nil // cleanup reference
+
+	if l.size-l.tidx > l.hidx {
+		copy(l.data[offset:], l.data[offset+1:l.tidx]) // shift to the left by one (slow operation, need ways to optimize this)
+		l.tidx--
+	} else {
+		copy(l.data[l.hidx+2:], l.data[l.hidx+1:offset])
+		l.hidx++
+	}
 
-	copy(l.data[offset:], l.data[idx+1:l.size]) // shift to the left by one (slow operation, need ways to optimize this)
 	l.size--
 	l.shrink()
 
diff --git a/list/arraylist/arraylist_test.go b/list/arraylist/arraylist_test.go
index c1dcca3..b8c7ef5 100644
--- a/list/arraylist/arraylist_test.go
+++ b/list/arraylist/arraylist_test.go
@@ -95,3 +95,49 @@ func TestPop(t *testing.T) {
 		t.Error("should not be ok, v = ", v)
 	}
 }
+
+func TestRemove(t *testing.T) {
+	l := New()
+	for i := 0; i < 5; i++ {
+		l.PushFront(uint(i))
+	}
+
+	var result string
+
+	for _, selval := range []uint{4, 3} {
+		last, _ := l.Index(selval)
+		if v, isfound := l.Remove(selval); isfound {
+			if v != last {
+				t.Error(v, " != ", last)
+			}
+		} else {
+			t.Error("should be found")
+		}
+	}
+
+	result = spew.Sprint(l.Values())
+	if result != "[4 3 2]" {
+		t.Error("should be [4 3 2], value =", result)
+	}
+
+	v, _ := l.Remove(1)
+	if v != uint(3) {
+		t.Error(v)
+	}
+
+	v, _ = l.Remove(1)
+	if v != uint(2) {
+		t.Error(v)
+	}
+
+	v, _ = l.Remove(1)
+	if v != nil && l.Size() != 1 {
+		t.Error(v)
+	}
+
+	v, _ = l.Remove(0)
+	if v != uint(4) && l.Size() != 0 {
+		t.Error(v, "size = ", l.Size())
+	}
+
+}