From 6b8435d5f66ffbc7d04e6f5f12d47b87fa0d1dd3 Mon Sep 17 00:00:00 2001
From: Shaun Reed <shaunrd0@gmail.com>
Date: Thu, 4 Jun 2020 08:48:45 -0400
Subject: [PATCH] Check return value when peeking linked lists

---
 cpp/datastructs/circledoublelist/circledoublelist.cpp | 3 ++-
 cpp/datastructs/circlesinglelist/circlesinglelist.cpp | 3 ++-
 cpp/datastructs/doublelist/doublelist.cpp             | 3 ++-
 cpp/datastructs/singlelist/singlelist.cpp             | 3 ++-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/cpp/datastructs/circledoublelist/circledoublelist.cpp b/cpp/datastructs/circledoublelist/circledoublelist.cpp
index 767baad..a8c2c16 100644
--- a/cpp/datastructs/circledoublelist/circledoublelist.cpp
+++ b/cpp/datastructs/circledoublelist/circledoublelist.cpp
@@ -187,7 +187,8 @@ int CircleDoubleList::peek() const
   if (!isEmpty())
     std::cout << "[" << tail->next->data << "] is at the top of our list\n";
   else std::cout << "Nothing to peek, our list is empty...\n";
-  return tail->data;
+  // If the list has data we return it, otherwise we return the smallest possible int (error)
+  return (!isEmpty()) ? tail->data : INT32_MIN;
 }
 
 /** print
diff --git a/cpp/datastructs/circlesinglelist/circlesinglelist.cpp b/cpp/datastructs/circlesinglelist/circlesinglelist.cpp
index 0f2390b..9027f3f 100644
--- a/cpp/datastructs/circlesinglelist/circlesinglelist.cpp
+++ b/cpp/datastructs/circlesinglelist/circlesinglelist.cpp
@@ -191,7 +191,8 @@ int CircleSingleList::peek() const
   if (!isEmpty())
     std::cout << "[" << tail->next->data << "] is at the top of our list\n";
   else std::cout << "Nothing to peek, our list is empty...\n";
-  return tail->next->data;
+  // If the list has data we return it, otherwise we return the smallest possible int (error)
+  return (!isEmpty()) ? tail->next->data : INT32_MIN;
 }
 
 /** print
diff --git a/cpp/datastructs/doublelist/doublelist.cpp b/cpp/datastructs/doublelist/doublelist.cpp
index 06df49e..4fd8182 100644
--- a/cpp/datastructs/doublelist/doublelist.cpp
+++ b/cpp/datastructs/doublelist/doublelist.cpp
@@ -168,7 +168,8 @@ int DoubleList::peek() const
   if (!isEmpty())
     std::cout << "[" << head->data << "] is at the top of our list\n";
   else std::cout << "Nothing to peek, our list is empty...\n";
-  return head->data;
+  // If the list has data we return it, otherwise we return the smallest possible int (error)
+  return (!isEmpty()) ? head->data : INT32_MIN;
 }
 
 /** print
diff --git a/cpp/datastructs/singlelist/singlelist.cpp b/cpp/datastructs/singlelist/singlelist.cpp
index 52d54bd..e469f53 100644
--- a/cpp/datastructs/singlelist/singlelist.cpp
+++ b/cpp/datastructs/singlelist/singlelist.cpp
@@ -168,7 +168,8 @@ int SingleList::peek() const
   if (!isEmpty())
     std::cout << "[" << head->data << "] is at the top of our list\n";
   else std::cout << "Nothing to peek, our list is empty...\n";
-  return head->data;
+  // If the list has data we return it, otherwise we return the smallest possible int (error)
+  return (!isEmpty()) ? head->data : INT32_MIN;
 }
 
 /** print