diff --git a/src/main/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedList.java b/src/main/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedList.java
index e162d23..e9b9153 100644
--- a/src/main/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedList.java
+++ b/src/main/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedList.java
@@ -96,9 +96,8 @@ public void removeFromEnd() {
             LinkedListNode previous = this.last.getPrevious();
             previous.setNext(null);
             this.last = previous;
+            this.totalElements--;
         }
-
-        this.totalElements--;
     }
 
     public void remove(final int position) {
diff --git a/src/main/java/io/github/diegourban/algorithms/datastructure/vector/Vector.java b/src/main/java/io/github/diegourban/algorithms/datastructure/vector/Vector.java
index 7430021..f0c4717 100644
--- a/src/main/java/io/github/diegourban/algorithms/datastructure/vector/Vector.java
+++ b/src/main/java/io/github/diegourban/algorithms/datastructure/vector/Vector.java
@@ -45,7 +45,7 @@ private boolean positionOccupied(final int position) {
     }
 
     public void remove(final int position) {
-        for(int i = position; i < this.totalElements; i++) {
+        for(int i = position; i < this.totalElements - 1; i++) {
             this.elements[i] = this.elements[i+1];
         }
         totalElements--;
diff --git a/src/test/java/io/github/diegourban/algorithms/datastructure/ElementTest.java b/src/test/java/io/github/diegourban/algorithms/datastructure/ElementTest.java
new file mode 100644
index 0000000..bd7c4ea
--- /dev/null
+++ b/src/test/java/io/github/diegourban/algorithms/datastructure/ElementTest.java
@@ -0,0 +1,24 @@
+package io.github.diegourban.algorithms.datastructure;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class ElementTest {
+
+    @Test
+    void shouldEqualAnElementWithTheSameName() {
+        assertThat(new Element("diego")).isEqualTo(new Element("diego"));
+        assertThat(new Element("diego")).isNotEqualTo(new Element("paulo"));
+    }
+
+    @Test
+    void shouldNotEqualNull() {
+        assertThat(new Element("diego")).isNotEqualTo(null);
+    }
+
+    @Test
+    void shouldPrintItsName() {
+        assertThat(new Element("diego")).hasToString("diego");
+    }
+}
diff --git a/src/test/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedListTest.java b/src/test/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedListTest.java
index 926e270..28ed1ae 100644
--- a/src/test/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedListTest.java
+++ b/src/test/java/io/github/diegourban/algorithms/datastructure/linkedlist/LinkedListTest.java
@@ -1,10 +1,12 @@
 package io.github.diegourban.algorithms.datastructure.linkedlist;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
 import io.github.diegourban.algorithms.datastructure.Element;
 import org.junit.jupiter.api.Test;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 class LinkedListTest {
 
     @Test
@@ -121,4 +123,76 @@ void shouldPrint() {
 
         assertThat(linkedList).hasToString("[diego,paulo,josé,]");
     }
+
+    @Test
+    void shouldAddAtPositionOfEmptyList() {
+        LinkedList linkedList = new LinkedList();
+        linkedList.add(0, new Element("diego"));
+
+        assertThat(linkedList.size()).isEqualTo(1);
+        assertThat(linkedList.get(0)).isEqualTo(new Element("diego"));
+    }
+
+    @Test
+    void shouldAddAtPositionEqualToSizeAsLast() {
+        LinkedList linkedList = new LinkedList();
+        linkedList.addAtEnd(new Element("diego"));
+        linkedList.add(1, new Element("paulo"));
+
+        assertThat(linkedList).hasToString("[diego,paulo,]");
+    }
+
+    @Test
+    void shouldRejectGettingAMissingPosition() {
+        LinkedList linkedList = new LinkedList();
+        linkedList.addAtEnd(new Element("diego"));
+
+        assertThatIllegalArgumentException().isThrownBy(() -> linkedList.get(1));
+        assertThatIllegalArgumentException().isThrownBy(() -> linkedList.get(-1));
+    }
+
+    @Test
+    void shouldRejectRemovingFromStartOfEmptyList() {
+        assertThatIllegalStateException().isThrownBy(() -> new LinkedList().removeFromStart());
+    }
+
+    @Test
+    void shouldBecomeEmptyAfterRemovingTheOnlyElementFromStart() {
+        LinkedList linkedList = new LinkedList();
+        linkedList.addAtEnd(new Element("diego"));
+        linkedList.removeFromStart();
+
+        assertThat(linkedList.size()).isZero();
+        assertThat(linkedList).hasToString("[]");
+    }
+
+    @Test
+    void shouldBecomeEmptyAfterRemovingTheOnlyElementFromEnd() {
+        LinkedList linkedList = new LinkedList();
+        linkedList.addAtEnd(new Element("diego"));
+        linkedList.removeFromEnd();
+
+        assertThat(linkedList.size()).isZero();
+        assertThat(linkedList).hasToString("[]");
+    }
+
+    @Test
+    void shouldRemoveFirstAndLastByPosition() {
+        LinkedList linkedList = new LinkedList();
+        linkedList.addAtEnd(new Element("diego"));
+        linkedList.addAtEnd(new Element("paulo"));
+        linkedList.addAtEnd(new Element("josé"));
+
+        linkedList.remove(0);
+        assertThat(linkedList).hasToString("[paulo,josé,]");
+
+        linkedList.remove(1);
+        assertThat(linkedList).hasToString("[paulo,]");
+        assertThat(linkedList.size()).isEqualTo(1);
+    }
+
+    @Test
+    void shouldPrintEmptyList() {
+        assertThat(new LinkedList()).hasToString("[]");
+    }
 }
diff --git a/src/test/java/io/github/diegourban/algorithms/datastructure/set/SetTest.java b/src/test/java/io/github/diegourban/algorithms/datastructure/set/SetTest.java
index 3f6b865..f532aae 100644
--- a/src/test/java/io/github/diegourban/algorithms/datastructure/set/SetTest.java
+++ b/src/test/java/io/github/diegourban/algorithms/datastructure/set/SetTest.java
@@ -1,9 +1,9 @@
 package io.github.diegourban.algorithms.datastructure.set;
 
-import org.junit.jupiter.api.Test;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
+import org.junit.jupiter.api.Test;
+
 class SetTest {
 
     @Test
@@ -12,7 +12,9 @@ void shouldAdd() {
         set.add("Diego");
         set.add("André");
         set.add("Zuleika");
-        assertThat(set).hasToString("[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Zuleika], [André], [], [], [Diego], [], [], []]");
+        assertThat(set)
+                .hasToString(
+                        "[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Zuleika], [André], [], [], [Diego], [], [], []]");
     }
 
     @Test
@@ -21,8 +23,34 @@ void shouldRemove() {
         set.add("Diego");
         set.add("André");
         set.add("Zuleika");
-        assertThat(set).hasToString("[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Zuleika], [André], [], [], [Diego], [], [], []]");
+        assertThat(set)
+                .hasToString(
+                        "[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Zuleika], [André], [], [], [Diego], [], [], []]");
         set.remove("André");
-        assertThat(set).hasToString("[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Zuleika], [], [], [], [Diego], [], [], []]");
+        assertThat(set)
+                .hasToString(
+                        "[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Zuleika], [], [], [], [Diego], [], [], []]");
+    }
+
+    @Test
+    void shouldIgnoreDuplicates() {
+        Set set = new Set();
+        set.add("Diego");
+        set.add("Diego");
+
+        assertThat(set)
+                .hasToString(
+                        "[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Diego], [], [], []]");
+    }
+
+    @Test
+    void shouldIgnoreRemovingAMissingWord() {
+        Set set = new Set();
+        set.add("Diego");
+        set.remove("Daniel");
+
+        assertThat(set)
+                .hasToString(
+                        "[[], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [Diego], [], [], []]");
     }
 }
diff --git a/src/test/java/io/github/diegourban/algorithms/datastructure/vector/VectorTest.java b/src/test/java/io/github/diegourban/algorithms/datastructure/vector/VectorTest.java
index 28efa45..6332813 100644
--- a/src/test/java/io/github/diegourban/algorithms/datastructure/vector/VectorTest.java
+++ b/src/test/java/io/github/diegourban/algorithms/datastructure/vector/VectorTest.java
@@ -1,10 +1,11 @@
 package io.github.diegourban.algorithms.datastructure.vector;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+
 import io.github.diegourban.algorithms.datastructure.Element;
 import org.junit.jupiter.api.Test;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 class VectorTest {
 
     @Test
@@ -26,10 +27,50 @@ void test() {
 
         vector.remove(1);
 
-        for(int i = 0; i < 300; i++) {
+        for (int i = 0; i < 300; i++) {
             Element e = new Element("Element " + i);
             vector.add(e);
         }
         System.out.println(vector);
     }
+
+    @Test
+    void shouldRejectAddingAtAnInvalidPosition() {
+        Vector vector = new Vector();
+        vector.add(new Element("Joao"));
+
+        assertThatIllegalArgumentException().isThrownBy(() -> vector.add(-1, new Element("Jose")));
+        assertThatIllegalArgumentException().isThrownBy(() -> vector.add(5, new Element("Jose")));
+    }
+
+    @Test
+    void shouldRejectGettingAnInvalidPosition() {
+        Vector vector = new Vector();
+        vector.add(new Element("Joao"));
+
+        assertThat(vector.get(0)).isEqualTo(new Element("Joao"));
+        assertThatIllegalArgumentException().isThrownBy(() -> vector.get(1));
+        assertThatIllegalArgumentException().isThrownBy(() -> vector.get(-1));
+    }
+
+    @Test
+    void shouldNotContainAMissingElement() {
+        Vector vector = new Vector();
+        vector.add(new Element("Joao"));
+
+        assertThat(vector.contains(new Element("Mario"))).isFalse();
+    }
+
+    @Test
+    void shouldRemoveFromAFullVector() {
+        Vector vector = new Vector();
+        for (int i = 0; i < 100; i++) {
+            vector.add(new Element("Element " + i));
+        }
+
+        vector.remove(0);
+
+        assertThat(vector.size()).isEqualTo(99);
+        assertThat(vector.get(0)).isEqualTo(new Element("Element 1"));
+    }
 }