fix(solutions): memory issues thanks to -fsanitize=address flag with gcc

challenges/reverse-polish-notation/solutions/c/function/character.c

@@ -1,8 +1,5 @@
 #include "character.h"
 
-#include <stdlib.h>
-#include <string.h>
-
 void character_append(char* string, char character) {
   size_t length = strlen(string);
   string[length] = character;

challenges/reverse-polish-notation/solutions/c/function/character.h

@@ -1,6 +1,9 @@
 #ifndef __CHARACTER__
 #define __CHARACTER__
 
+#include <stdlib.h>
+#include <string.h>
+
 /**
  * @brief Append a character to a string, assuming string points to an array
  * with enough space.

challenges/reverse-polish-notation/solutions/c/function/input.c

@@ -1,10 +1,5 @@
 #include "input.h"
 
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "character.h"
-
 char* input() {
   char character;
   size_t length = 1;

challenges/reverse-polish-notation/solutions/c/function/input.h

@@ -1,6 +1,11 @@
 #ifndef __INPUT__
 #define __INPUT__
 
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "character.h"
+
 /**
  * @brief Read a line from stdin.
  *

challenges/reverse-polish-notation/solutions/c/function/solution.c

@@ -20,7 +20,7 @@ bool is_integer(char* string) {
 
 int main() {
   char* string = input();
-  struct Stack* stack = stack_initialization();
+  struct stack* stack = stack_initialization();
   char* token = strtok(string, " ");
   while (token != NULL) {
     if (is_integer(token)) {
@@ -45,5 +45,7 @@ int main() {
     token = strtok(NULL, " ");
   }
   printf("%ld\n", (intptr_t)stack_pop(stack));
+  free(string);
+  stack_free(stack);
   return EXIT_SUCCESS;
 }

challenges/reverse-polish-notation/solutions/c/function/stack.c

@@ -1,11 +1,9 @@
 #include "stack.h"
 
-#include <stdio.h>
-#include <stdlib.h>
-
-struct Stack *stack_initialization() {
-  struct Stack *stack = malloc(sizeof(*stack));
+struct stack *stack_initialization() {
+  struct stack *stack = malloc(sizeof(struct stack));
   if (stack == NULL) {
+    perror("Error (stack_initialization)");
     exit(EXIT_FAILURE);
   }
   stack->first = NULL;
@@ -13,9 +11,15 @@ struct Stack *stack_initialization() {
   return stack;
 }
 
-void stack_push(struct Stack *stack, void *data) {
-  struct Node *node_new = malloc(sizeof(*node_new));
-  if (stack == NULL || data == NULL) {
+void stack_push(struct stack *stack, void *data) {
+  if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (stack_push)");
+    exit(EXIT_FAILURE);
+  }
+  struct stack_node *node_new = malloc(sizeof(struct stack_node));
+  if (data == NULL) {
+    perror("Error (stack_push)");
     exit(EXIT_FAILURE);
   }
   node_new->data = data;
@@ -24,11 +28,13 @@ void stack_push(struct Stack *stack, void *data) {
   stack->length = stack->length + 1;
 }
 
-void *stack_pop(struct Stack *stack) {
+void *stack_pop(struct stack *stack) {
   if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (stack_pop)");
     exit(EXIT_FAILURE);
   }
-  struct Node *node = stack->first;
+  struct stack_node *node = stack->first;
   void *data = NULL;
   if (node != NULL) {
     stack->first = node->next;
@@ -38,3 +44,18 @@ void *stack_pop(struct Stack *stack) {
   stack->length = stack->length - 1;
   return data;
 }
+
+void stack_free(struct stack *stack) {
+  if (stack == NULL) {
+    errno = EINVAL;
+    perror("Error (stack_free)");
+    exit(EXIT_FAILURE);
+  }
+  struct stack_node *node = stack->first;
+  while (node != NULL) {
+    struct stack_node *node_next = node->next;
+    free(node);
+    node = node_next;
+  }
+  free(stack);
+}

challenges/reverse-polish-notation/solutions/c/function/stack.h

@@ -1,23 +1,54 @@
 #ifndef __STACK__
 #define __STACK__
 
+#include <errno.h>
+#include <stdio.h>
 #include <stdlib.h>
 
-// LIFO = Last In First Out
-struct Stack {
-  struct Node *first;
+/**
+ * @brief Stack structure => LIFO (Last In First Out).
+ */
+struct stack {
+  struct stack_node *first;
   size_t length;
 };
 
-struct Node {
+/**
+ * @brief Stack node structure.
+ */
+struct stack_node {
   void *data;
-  struct Node *next;
+  struct stack_node *next;
 };
 
-struct Stack *stack_initialization();
+/**
+ * @brief Stack initialization.
+ *
+ * @return struct stack*
+ */
+struct stack *stack_initialization();
 
-void stack_push(struct Stack *stack, void *data);
+/**
+ * @brief Push data to stack.
+ *
+ * @param stack
+ * @param data
+ */
+void stack_push(struct stack *stack, void *data);
 
-void *stack_pop(struct Stack *stack);
+/**
+ * @brief Pop data from stack.
+ *
+ * @param stack
+ * @return void*
+ */
+void *stack_pop(struct stack *stack);
+
+/**
+ * @brief Frees the stack.
+ *
+ * @param stack
+ */
+void stack_free(struct stack *stack);
 
 #endif