From 4b06a1587ee338541c70473750795e7dbef3b734 Mon Sep 17 00:00:00 2001
From: Maalvika Bhat <mbhat@olin.edu>
Date: Thu, 6 Feb 2020 12:06:46 -0500
Subject: [PATCH] Submission

---
 exercises/ex02/adder.c  | 57 +++++++++++++++++++++++++++++++++++++++++
 exercises/ex02/aspace.c | 23 ++++++++++++-----
 exercises/ex02/stack.c  | 18 ++++++-------
 3 files changed, 81 insertions(+), 17 deletions(-)
 create mode 100644 exercises/ex02/adder.c

diff --git a/exercises/ex02/adder.c b/exercises/ex02/adder.c
new file mode 100644
index 00000000..63d48c9a
--- /dev/null
+++ b/exercises/ex02/adder.c
@@ -0,0 +1,57 @@
+/*
+ * Exercise 2
+ * Maalvika Bhat
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int processInput(char input[]) {
+	int val = atoi(input);
+
+	if (val == 0) {
+		puts("input not valid");
+	} else if (strlen(input) > 10) {
+		puts("input is too large");
+	} else {
+		printf("input of %i has been added\n", val);
+		return val;
+	}
+	return 0;
+}
+
+void addIntegers(int integers[]) {
+	int sum = 0;
+	for (int i = 0; i < 10; ++i) {
+		sum += integers[i];
+	}
+	printf("final sum of all the integers is %i\n", sum);
+}
+
+void run() {
+	char input[5];
+	int integers[10];
+	int count = 0;
+
+	puts("enter up to 10 integers to add");
+	while (scanf("%10s", input) != EOF) {
+		if (count < 10) {
+			int result = processInput(input);
+
+			if (result != 0) {
+				integers[count] = result;
+				count++;
+			}
+		} else {
+			puts("press CTRL+D to add the integers up");
+			continue;
+		}
+	}
+	addIntegers(integers);
+}
+
+int main() {
+	run();
+	return 0;
+}
diff --git a/exercises/ex02/aspace.c b/exercises/ex02/aspace.c
index 6403e0ac..28cdb444 100644
--- a/exercises/ex02/aspace.c
+++ b/exercises/ex02/aspace.c
@@ -1,15 +1,13 @@
-/* Example code for Think OS.
-
-Copyright 2014 Allen Downey
-License: GNU GPLv3
-
-*/
-
 #include <stdio.h>
 #include <stdlib.h>
 
 int var1;
 
+void printLocalVariable() {
+	int a = 0;
+	printf("Address of local variable a is %p\n", &a);
+}
+
 int main ()
 {
     int var2 = 5;
@@ -22,5 +20,16 @@ int main ()
     printf ("p points to %p\n", p);
     printf ("s points to %p\n", s);
 
+  p = malloc(10);
+	printf ("Address of p is now %p\n\n", p);
+
+	printLocalVariable();
+
+	void *b = malloc(10);
+	void *c = malloc(10);
+
+	printf ("Address of b is %p\n", b);
+	printf ("Address of c is %p\n\n", c);
+
     return 0;
 }
diff --git a/exercises/ex02/stack.c b/exercises/ex02/stack.c
index 61d2568a..442d648a 100644
--- a/exercises/ex02/stack.c
+++ b/exercises/ex02/stack.c
@@ -1,10 +1,3 @@
-/* Example code for Think OS.
-
-Copyright 2014 Allen Downey
-License: GNU GPLv3
-
-*/
-
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -12,7 +5,7 @@ License: GNU GPLv3
 
 int *foo() {
     int i;
-    int array[SIZE];
+    int array[SIZE]; // local array
 
     printf("%p\n", array);
 
@@ -24,7 +17,7 @@ int *foo() {
 
 void bar() {
     int i;
-    int array[SIZE];
+    int array[SIZE]; //  local array
 
     printf("%p\n", array);
 
@@ -36,7 +29,7 @@ void bar() {
 int main()
 {
     int i;
-    int *array = foo();
+    int *array = foo(); // assigning a pointer to a function's local array
     bar();
 
     for (i=0; i<SIZE; i++) {
@@ -45,3 +38,8 @@ int main()
 
     return 0;
 }
+
+/* The arrays initialized in foo() and bar() are located at the same address.
+ * Both arrays were local variables that were only stored in the stack while
+ * their respective functions were running.
+ */