Add ex2

There is still a memory leak in row 16 and 103.

ex2/ex2.c

@@ -6,8 +6,129 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdbool.h>
+
+typedef struct list_t {
+    int *value;
+    struct list_t *next;
+} list;
+
+list *create() {
+    list *li = malloc(sizeof(list));
+    li->value = NULL;
+    li->next = NULL;
+    return li;
+}
+
+void destroy(list *li) {
+    while (li != NULL) {
+        list *tmp = li;
+        li = li->next;
+        free(tmp);
+    }
+    free(li);
+    li = NULL;
+}
+
+list *push(list *li, int *value) {
+    list *new = create();
+    new->value = value;
+    new->next = li;
+    return new;
+}
+
+list *push_at_index(list *li, int *value, int index) {
+    list *previous = NULL;
+    list *current = li;
+    int current_index = 0;
+
+    // Search the list index
+    while (current_index < index && current != NULL) {
+        current_index++;
+        previous = current;
+        current = current->next;
+    }
+
+    // Push the value at this index
+    list *new = create();
+    new->value = value;
+    new->next = current;
+    if (previous != NULL) {
+        previous->next = new;
+    } else {
+        return new;
+    }
+
+    return li;
+}
+
+list *remove_from_index(list *li, int index) {
+    list *previous = NULL;
+    list *current = li;
+    int current_index = 0;
+
+    // Search the list index
+    while (current_index < index && current != NULL) {
+        current_index++;
+        previous = current;
+        current = current->next;
+    }
+
+    // Remove from index
+    if (current != NULL) {
+        if (previous != NULL) {
+            previous->next = current->next;
+        } else {
+            li = li->next;
+        }
+        free(current);
+    }
+    return li;
+}
+
+void print(list *li) {
+    while (li != NULL && li->value) {
+        printf("%d ", *li->value);
+        li = li->next;
+    }
+    printf("\n");
+}
 
 int main() {
+    const int ARGUMENTS_COUNT = 6;
+    const int INSERT_INDEX = 4;
+    const int REMOVE_INDEX = 5;
+    int value_to_insert = 0;
+    int *array = malloc(sizeof(int) * ARGUMENTS_COUNT);
+
+    list *li = create();
+
+    // Get the values
+    for (int i = 0; i < ARGUMENTS_COUNT; i++) {
+        int value;
+        scanf("%d", &value);
+        array[i] = value;
+    }
+
+    // Execute the work
+    for (int i = 0; i < ARGUMENTS_COUNT; i++) {
+        if (i < 4) {
+            li = push(li, &array[i]);
+            if (i == 0) {
+                li->next = NULL;
+            }
+        }
+        else if (i == INSERT_INDEX) {
+            li = push_at_index(li, &value_to_insert, array[i]);
+            print(li);
+        }
+        else if (i == REMOVE_INDEX) {
+            li = remove_from_index(li, array[i]);
+            print(li);
+        }
+    }
+
+    // Free the memory and exit the program
+    destroy(li);
+    free(array);
     return EXIT_SUCCESS;
 }